Drainage device for siphon action toilet

ABSTRACT

A toilet  10  has a bowl  20 , a connection pathway  31 , an ascending pathway  32 , and a descending pathway  33  across a weir  34 . The descending pathway  33  includes an expanded section  33   a  having a greater pipeline diameter and a tapered end  33   b  having a narrower opening area than that of the expanded section  33   a , and is connected with a drain socket  70 . The drain socket  70  has an inner drain conduit socket member  72  that is attached to be located inside a drain conduit  90 . The inner drain conduit socket member  72  has an extended socket section  75 , which is located below a floor surface FL of a lavatory and has a greater pipeline diameter, and a tapered conduit section  76 , which has a narrowed diameter. These sections  75  and  76  constitute a siphon action induction module.

RELATED APPLICATIONS

[0001] The present application is a divisional application of co-pending U.S. application Ser. No. 10/111,125, filed Apr. 18, 2002, which is the U.S. National stage filing for PCT Application No. PCT/JP00/07525, filed Oct. 26, 2000, and is also related to U.S. application Ser. No. ______, filed May 19, 2003, entitled “SIPHON ACTION TOILET,” all of which are commonly assigned and incorporated by reference herein in their entirety.

TECHNICAL FIELD

[0002] The present invention relates to a toilet that induces siphon action to cleanse excrement out of a toilet bowl, a drainage device used for induction of the siphon action, and a lavatory with such a toilet placed therein.

BACKGROUND ART

[0003] There has been a high demand for saving water used for cleansing a toilet. A decrease in flow rate of cleansing water fulfills such requirement of water saving. The simple decrease in quantity of cleansing water flown along the toilet bowl, however, leads to insufficient cleansing of the bowl and lowers the certainty of transporting and discharging excrement with cleansing water out of the toilet. The widely applied technique devices the shape of a trap in the toilet body to induce the siphon action in the flow of cleansing water and suck water kept in the bowl by means of the siphon action, thereby saving water.

[0004] A drain socket is often used for induction of the siphon action. For example, JAPANESE PATENT LAID-OPEN GAZETTE No. 8-326136 has proposed a drain socket shown in FIG. 80. In the illustrated prior art structure of the toilet, a drainage port 102J of a toilet body 100J is connected to a drain conduit P set on a floor surface FL via a drain socket 110J. The drain socket 110J is curved in a longitudinal direction of the toilet body 100J. The drain socket 110J has a curved socket flow path 112J formed therein and a concaved trap receiving section 111J on the wall surface thereof. In the drain socket 110J, a turbulent flow is generated by the curved flow path and the concaved trap receiving section to facilitate induction of the siphon action.

[0005] A restriction element 116J is provided on the joint of the drain socket 110J with the drain conduit P, that is, between a flow outlet 114J of the socket flow path 112J and the upper end of the drain conduit. The restriction element 116J functions to temporarily retain the flow of cleansing water through the socket flow path 112J into the drain conduit P, thus accelerating induction of the siphon action.

[0006] The conventional restriction element 116J is formed separately from the drain socket 110J and is simply interposed between the drain socket 110J and the opening on the upper end of the drain conduit P. The restriction element 116J is thus readily shifted in position or falls into the drain conduit P by the force applied for drainage. The positional shift of the restriction element reduces the effect of inducing the siphon action. The fall of the restriction element into the drain conduit P may clog the drain conduit P. Attachment of the restriction element to a preset position is rather troublesome.

[0007] The object of the present invention is thus to enhance the suction efficiency of reserved water in the bowl by the siphon action, regardless of the shape of the trap.

[0008] The object of the present invention is also to provide a drain socket that attains quick induction of the siphon action without any positional deviation of the restriction element and has excellent workability.

[0009] The drain socket 110J is provided with the curved flow path and the concaved trap receiving section 111J on the inner wall surface thereof, and accordingly has the complicated conduit structure. Cutting dies of a die assembly having a complicated shape are accordingly required, for example, in the case of injection molding the drain socket 110J. From the viewpoint of molding ability, it is required to modify the complicated structure of the drain socket 110J. The siphon action 110J can thus not be designed to have the optimum shape for inducing the siphon action.

[0010] The object of the present invention is thus to provide a drain socket that has a simple construction, is easily manufactured, ensures instant induction of the siphon action, and gives a sufficient power of siphon action.

[0011] The distance between the floor surface or the wall surface on which the toilet is installed (hereinafter referred to as the installation plane) and the end of the drain conduit depends upon the type of the toilet. A variety of drain sockets having different heights are thus required as products for installation of diverse toilets via the drain socket. This interferes with efficient reduction in number of different products of drain socket.

[0012] The toilets are independently designed and manufactured by a large number of manufacturers in the world, and it is practically impossible to prepare drain sockets corresponding to all options of the diverse toilets. For example, when the distance between the installation plane of the toilet and the end of the drain conduit is longer than the length of the drain socket, a plate member or any equivalent member is laid under the drain socket to supplement the insufficient length. This, however, worsens the working efficiency. When the distance between the installation plane of the toilet and the end of the drain conduit is shorter than the length of the drain socket, on the other hand, a flange is inconveniently used for connection of the toilet with a soil pipe. The connecting function of the drain socket is accordingly not usable for some types of the toilets.

[0013] In the prior art drain socket, the hollow cylindrical space defined in the socket is used as the flow path of water. The position of the restriction element disposed in the flow path is not changeable in each field. For example, in the case of the siphon action-type toilet, the location of the restriction element below the floor surface enhances the sucking force of reserved water or cleansing water by the induced siphon action. The prior art drain socket, however, does not allow such change of the position. The prior art drain socket attains the continuous siphon action, but has a significant loss of the sucking force of reserved water or cleansing water by the continuous siphon action.

[0014] The object of the present invention is thus to provide a drain socket applicable to various types of toilets and diverse conditions of installation fields.

[0015] The siphon action disappears when the siphon pipeline is not filled with water (cleansing water) due to invasion of the air or a decrease in flow rate. In the above cited reference, a decrease in quantity of cleansing water in the toilet lowers the flow rate of cleansing water flown into the drain socket and thus reduces the quantity of the water current changing its direction in the curved socket flow path. The reduced quantity lowers the degree of change in direction of the water current and causes the cleansing water to be directly flown into the drain conduit outside the toilet. This decreases the ratio of the occupation area of cleansing water to the cross section of the conduit and easily allows invasion of the air from the downstream. The siphon action then discontinues and disappears. In general, excrement (toilet paper and floating diarrheal stool) floating in the reserved water in the bowl is sucked into the trap and discharged in the terminal stage of the siphon action. The prior art technique often causes disappearance of the siphon action in its terminal stage with a reduced flow rate and may not completely suck or discharge the floating excrement.

[0016] The object of the present invention is thus to enhance the sucking efficiency of reserved water in the bowl in the terminal stage of the siphon action.

[0017] In the siphon action-type toilet, it is preferable to induce a high-speed siphon action in the initial stage of the cleansing process and quickly flow out excrement with a high water head and a low pressure loss. This enables excrement in the bowl to be discharged with a less quantity of cleansing water and saves water. Shortening the time of flow of cleansing water for the purpose of water saving may cause floating excrement in the bowl not to be smoothly discharged but to partly remain, while large excrement and paper are quickly flown out.

[0018] The object of the present invention is thus to attain quick discharge of floating excrement in the bowl.

DISCLOSURE OF THE INVENTION

[0019] At least part of the above and the other related objects is attained by a first toilet of the present invention, which includes a bowl that keeps cleansing water as reserved water during a non-cleansing time and a trap module that defines a conduit, through which a new supply of cleansing water fed to the bowl is flown out together with the remaining reserved water. The trap module has: an ascending conduit that defines an ascending pathway connecting with the bowl; and a drain conduit that defines a draining pathway for leading a flow of cleansing water passing through the ascending conduit to outside of the toilet. The drain conduit is provided with a retention module that causes the flow of cleansing water to be temporarily retained in the course of passage through the draining pathway, so as to induce a siphon action. The drain conduit includes a protruded conduit section that is part of the draining pathway protruded downward from a floor surface on which the toilet is installed. The retention module is disposed in the protruded conduit section.

[0020] In the first toilet of the present invention having the above construction, the trap module has the ascending pathway and the drain conduit connecting thereto. Part of the draining pathway is protruded below the floor surface, on which the toilet is installed, to form the protruded conduit section. The retention module induces the siphon action in the protruded conduit section. There is a large difference between the level of cleansing water temporarily retained in the protruded conduit section by means of the retention module and the level of reserved water in the bowl. This increases the different in water head at the time of induction of the siphon action and thereby enhances the sucking force of reserved water and the suction efficiency of the siphon action.

[0021] In accordance with one preferable application of the first toilet of the present invention, the drain conduit has a plurality of the retention modules. At least one of the plural retention modules is disposed in the protruded conduit section of the draining pathway, while at least another one of the plural retention modules is disposed in the draining pathway other than the protruded conduit section.

[0022] The retention modules at a plurality of different places respectively induce the siphon action and thus enhance the sucking force of reserved water and the suction efficiency by the siphon action.

[0023] The retention module of the protruded conduit section may be located in a neighborhood of or on one end of the draining pathway.

[0024] This arrangement increases the water head difference in the process of inducing the siphon action and thus advantageously enhances the sucking force of reserved water and the suction efficiency by the siphon action.

[0025] The retention module may be an enlarged conduit section having an enlarged conduit diameter to allow temporary retention of the flow of cleansing water, or alternatively may be a contracted conduit section having a narrower diameter to allow temporary retention of the flow of cleansing water.

[0026] The enlarged conduit section or the contracted conduit section temporarily retains the flow of cleansing water and thus effectively induces the siphon action.

[0027] The retention module may include a plurality of the contracted conduit sections or more specifically have upper and lower contracted conduit sections along the draining pathway. This arrangement enhances the effect of inducing the siphon action and thus improves the sucking force of reserved water and the suction efficiency.

[0028] The contracted conduit section may be formed by extending a range of a narrowed conduit diameter along a longitudinal axis of the draining pathway.

[0029] The contracted conduit section of this structure retains the flow of cleansing water for a relatively long time and then allows passage of the cleansing water through this contracted conduit section. This arrangement extends the time of inducing the siphon action and thereby enhances the sucking force of reserved water and the suction efficiency.

[0030] The trap module may be formed separately from a toilet body having the bowl and is attached to the toilet body. The drain conduit may have a separate drain conduit section including the protruded conduit section, and the separate drain conduit section is attached to the other part of the draining pathway to complete the drain conduit.

[0031] The pottery toilet body is not required to have any projection from the bottom. This structure is advantageous in manufacture, installation, transport, and wrapping. The place of attachment may be sealed with a sealing member to attain water tightness of the drain conduit. This desirably prevents leakage of cleansing water and excrement from the drain conduit. One end of the protruded conduit section, which is formed separately from the other part of the draining pathway, may be located in an existing external drain conduit set in the floor on which the toilet is installed. This allows utilization of the existing toilet body and is thus advantageous in manufacture.

[0032] At least part of the above objects is attained by a first drain socket that is connected to a toilet, in order to discharge a flow of cleansing water from the toilet to an external drain conduit set in a floor on which the toilet is installed. The drain socket includes: a connection unit that is connected to one end of an inner-toilet trap conduit to flow out cleansing water kept as reserved water in a bowl of the toilet during a non-cleansing time, together with a new supply of cleansing water fed to the bowl; and a conduit defining member that is joined with the connection unit and defines a draining pathway communicating with the inner-toilet trap conduit. The conduit defining member forms the draining pathway that reaches inside of the external drain conduit. The conduit defining member has a retention module that causes a flow of cleansing water to be temporarily retained in a specific part of the draining pathway located inside the external drain conduit, so as to induce a siphon action.

[0033] The drain socket of the above construction is connected to the end of the inner-toilet trap conduit of the toilet, in order to discharge the flow of cleansing water from the toilet to the external drain conduit. Like the toilet discussed above, there is a large difference between the level of cleansing water temporarily retained by the retention module and the level of reserved water in the bowl. This drain socket induces the siphon action under the condition of the large water head difference and thus enhances the sucking force of reserved water and the suction efficiency by the siphon action. The drain socket is connectable to the existing toilet and accordingly allows utilization of the existing toilet body. This is advantageous in manufacture.

[0034] In the drain socket, the conduit defining member may have a plurality of the retention modules, or may be provided with the retention module in a neighborhood of or on one end of the draining pathway.

[0035] The retention modules at a plurality of different places increase the water head difference in the process of inducing the siphon action, thus enhancing the sucking force of reserved water and the suction efficiency by the siphon action.

[0036] In accordance with one preferable application, the connection unit has an element that is positioned and fixed in the inner-toilet trap conduit, and the conduit defining member includes an element that is positioned relative to the external drain conduit and is fixed on the floor surface, on which the toilet is installed.

[0037] This arrangement effectively prevents the drain socket from being shifted relative to the toilet or the external drain conduit by the force of the flow of cleansing water in the process of cleansing the toilet and ensures stable induction of the siphon action.

[0038] The conduit defining member may define the draining pathway by laying a connection part of the drain conduit joined with the connection unit and the specific part of the draining pathway inside the external drain conduit in an eccentric manner. This arrangement enables the inner-toilet trap conduit to be connected to the external drain conduit by means of the drain conduit of the drain socket even when the inner-toilet trap conduit is misaligned with the external drain conduit.

[0039] At least part of the above objects is attained by a lavatory with a toilet that is connected to an external drain conduit set in a floor, on which the toilet is installed. The external drain conduit has a retention module that is disposed in a specific pipeline section, through which cleansing water passing through an inner-toilet draining pathway flows. The retention module causes the flow of cleansing water to be temporarily retained, so as to induce a siphon action.

[0040] In the lavatory of the above construction, the external drain conduit is provided with the retention module to induce the siphon action, like the toilet discussed above. Connection of the existing toilet to the external drain conduit directly or via a drain socket enables cleansing water used for cleansing the toilet to be effectively discharged through induction of the siphon action. Locating the retention module below the floor surface, on which the toilet is installed, induces the siphon action under the condition of the large water head difference and enables the toilet to be effectively cleansed with the high sucking force of reserved water and the high suction efficiency. In this application, the toilet may or may not have the function of inducing the siphon action. This arrangement accordingly has the enhanced flexibility.

[0041] At least part of the above objects is attained by a first drainage device of a toilet, which includes: a drain socket that has a flow inlet connecting with a drainage port of a toilet body, a flow outlet connecting with a drain conduit leading to sewer, and a socket flow path connecting the flow inlet with the flow outlet in an eccentric layout; and a restriction element that is formed integrally with the drain socket and causes a flow of cleansing water flowing through the socket flow path to be temporarily retained, so as to induce a siphon action.

[0042] In the first drainage device of the present invention, cleansing water discharged out of the toilet body is flown out to the drain conduit through the flow inlet, the socket flow path, and the flow outlet of the drain socket. The drain socket has the flow inlet and the flow outlet that are eccentric to each other. The flow of cleansing water is accordingly curved along the eccentric flow path to be retained. The restriction element enhances the effect of retaining the flow of cleansing water and thereby induces the siphon action. Compared with the structure of retaining the flow of cleansing water by the single restriction element or by the single eccentric flow path, this structure with the combination of the eccentric flow path and the restriction element desirably prevents the excessively curved flow path or the excessively narrowed restricted flow path but ensures smooth discharge of excrement.

[0043] The restriction element is formed integrally with the drain socket and is thus not shifted nor stripped off by the force of cleansing water in the drainage process. This arrangement ensures induction of the desired siphon action and attains easy maintenance. The integral formation of the restriction element with the drain socket does not require positioning in forward or backward attachment of the drain socket and has the excellent workability.

[0044] The restriction element is disposed at various locations preferable for induction of the siphon action and has diverse shapes. For example, the restriction element may be formed as a restricted flow path eccentric to the socket flow path at the position of the restriction element. Combination with the flow in the eccentric socket flow path has the better effect. The restriction element may be disposed in a neighborhood of the flow outlet. This arrangement increases the quantity of cleansing water retained in the upstream by means of the restriction element, thus heightening the power of the siphon action and enhancing the discharge power of excrement.

[0045] In another preferable application, the socket flow path is extended below a fixation unit of the drain socket, which is fixed to the floor surface, and the restriction element is disposed on the lower end of the extended flow path. This arrangement also effectively increases the quantity of cleansing water retained by the restriction element.

[0046] The restriction element is formed integrally with the drain socket, so that there is no need of specifying the position of attachment in the work of installing the toilet. This arrangement attains the excellent workability. Here the ‘integrally formed’ state means integration in the work of installing the toilet to ensure the good workability. The restriction element may thus be molded integrally with the drain socket, or may be molded separately from the drain socket but assembled together to ensure fixation and positioning.

[0047] For effective induction of the siphon action, a toilet restriction unit may be provided in a neighborhood of the drainage port of the toilet, and the toilet restriction unit may be located to be eccentric to the flow inlet.

[0048] At least part of the above objects is attained by a second drainage device of a toilet, which includes: a drain socket having a toilet connection member with a flow inlet that connects with a drainage port of a toilet body, a drain conduit connection member with a flow outlet that connects with a drain conduit leading to sewer; and a socket flow path that connects the flow inlet with the flow outlet; and a cleansing water retention module that is formed separately from the drain socket, is fixed to the drain socket, and causes a flow of cleansing water flowing through the socket flow path to be temporarily retained, so as to induce a siphon action.

[0049] In the second drainage device of the present invention, excrement and cleansing water discharged from the toilet body pass through the drainage port and the socket flow path of the drain socket and are flown out of the flow outlet to the drain conduit. The cleansing water retention module is fixed to the drain socket. The cleansing water retention module temporarily retains the flow of cleansing water in the socket flow path and thereby induces the siphon action. The cleansing water retention module is formed separately from the drain socket. This enables the drain socket to have the simple construction and to be manufactured by taking into account only the optimum design condition for induction of the siphon action.

[0050] The drain socket has the simple construction and is readily manufactured without any restriction of the manufacturing conditions, for example, removal from the die, in injection or another molding process. The cleansing water retention module is designed to meet the optimum condition for induction of the siphon action when being fixed to the drain socket, and ensures quick induction of the sufficient siphon action without any restriction of the manufacturing condition.

[0051] In one preferable embodiment, the cleansing water retention module is designed to change a flow path area in a flow direction of cleansing water. One preferable embodiment of changing the flow path area continuously decreases the flow path area from the upstream side to the downstream side of the socket flow path. Another preferable embodiment of changing the flow path area provides a restriction element that partly narrows the flow path area. In one preferable embodiment, the restriction element is formed to reduce its flow path area from the upstream side to the downstream side.

[0052] The cleansing water retention module may have an enlarged flow path, which is formed upstream of the restriction element to have a greater flow path area, or may be provided with a plurality of restriction elements. These arrangements desirably ensure quick induction of the siphon action of the cleansing water flowing through the socket flow path, thus effectively saving water.

[0053] In the structure of the cleansing water retention module with the restriction element, the restriction element may be positioned in a neighborhood of the flow outlet. This arrangement increases the power of the siphon action specified by the difference between the water level of cleansing water reserved in the bowl of the toilet body and the water level in the flow outlet, thus attaining the excellent drainage performance.

[0054] The cleansing water retention module may have a fixation unit that is positioned and fixed to the drain socket. This arrangement effectively prevents a shift of the cleansing water retention module relative to the drain socket by the force of the flow of cleansing water and thus ensures induction of the stable siphon action.

[0055] At least part of the above objects is attained by a second drain socket that is connected to a toilet. The toilet has a bowl, in which cleansing water is kept as reserved water during a non-cleansing time, and a drain conduit for flowing out the reserved water together with a new supply of cleansing water fed to the bowl. The drain socket connects the drain conduit with an outside soil pipe and makes the reserved water or cleansing water flown from the drain conduit into the soil pipe. The drain socket includes at least two members separable in a flow direction of the reserved water or cleansing water.

[0056] The drain socket consists of the at least two members separable in the flow direction of reserved water or cleansing water. Various combinations of the at least two members attain diverse forms of the flow path of reserved water or cleansing water.

[0057] It is preferable that the drain socket further has a variable module that varies a length of the drain socket in the flow direction of the reserved water or cleansing water. This arrangement allows connection of the toilet with the soil pipe in a plurality of different layouts, thus ensuring application of the same drain socket to such different layouts.

[0058] In accordance with one preferable application, the at least two members separable in the flow direction of reserved water of cleansing water include at least a first member that is arranged in either a floor surface or a wall surface with the soil pipe embedded therein, and a second member combined with the first member. The drain socket further has a positional relation change module that changes a positional relation between the first member and the second member. The positional relation change module is activated to change the positional relation, so as to vary the length of the drain socket in the flow direction of the reserved water or cleansing water. The length of the drain socket is variable relative to the floor surface or the wall surface as the reference. The same drain socket is thus applicable to connect the toilet having different distances between the floor surface or the wall surface and the drain conduit with the soil pipe. This enhances the applicability.

[0059] In one preferable embodiment, the drain socket further has a display unit that is disposed in at least one of the first member and the second member to display information with regard to the varied length of the drain socket. This enables the length of the drain socket to be adjusted while checking the varied whole length of the drain socket, thus enhancing the workability in adjustment. A distance between either the floor surface or the wall surface with the soil pipe embedded therein and a connection of the drain socket with the drain conduit may be displayed in the display unit as the information with regard to the length. In this arrangement, there is no requirement of positioning the drain socket to the drain conduit of the toilet and adjusting the size to adequately connect the drain socket with the drain conduit of the toilet. The only required operation is to measure the distance between the floor surface or the wall surface and the position of connection of the drain socket with the drain conduit and adjusts the size of the drain socket based on the measurement. This ensures the smooth adjustment work.

[0060] In accordance with another preferable application, the at least two members separable in the flow direction of the reserved water or cleansing water include at least a first flow path defining member that defines a flow path communicating with an end of the drain conduit, and a second flow path defining member that is constructed separately from the first flow path defining member and extends the flow path defined by the first flow path defining member to a downstream side. The drain socket further has a flow path change module that changes a length of an extended flow path by the second flow path defining member. The flow path change module is activated to change the length of the extended flow path by the second flow path defining member, so as to vary the length of the drain socket in the flow direction of the reserved water or cleansing water. This arrangement allows the flow path length of the drain socket to be changed to a desired length.

[0061] In one preferable embodiment, the second flow path defining member includes a plurality of members, and the flow path change module changes the length of the extended flow path by a combination of the plurality of members. This arrangement enables the flow path length of the drain socket to be easily changed by the simple operation.

[0062] In accordance with one preferable application, the second flow path defining member has a mark set in advance to show a cutting position of the second flow path defining member, and the length of the extended flow path by the second flow path defining member is changed by cutting the second flow path defining member based on the mark. This arrangement allows the flow path of the drain socket to be cut to a desired length and facilitates the cutting work. In the above application, the second flow path defining member is capable of extending the flow path defined by the first flow path defining member to be lower than an installation plane of the toilet, and a distance of the extended flow path by the second flow path defining member to be lower than the installation plane of the toilet is displayed in advance in a vicinity of the mark. The length of the second flow path defining member is specified not to interfere with the sewer located below the installation plane of the toilet.

[0063] In accordance with another preferable application, the second flow path defining member is detachably attached to a predetermined site of the drain socket, and the length of the extended flow path by the second flow path defining member is changed by shifting a position of attachment of the second flow path defining member. This arrangement allows the flow path length of the drain socket to be readily changed by the simple operation.

[0064] In one preferable embodiment, a first flow path defining member that defines a flow path communicating with an end of the drain conduit, and a second flow path defining member that is constructed separately from the first flow path defining member and extends the flow path defined by the first flow path defining member to a downstream side are provided as the at least two members separable in the flow direction of the reserved water or cleansing water. The first flow path defining member includes a first member that is arranged in either a floor surface or a wall surface with the soil pipe embedded therein, and a second member combined with the first member. The drain socket further has a flow path change module that changes a length of an extended flow path by the second flow path defining member, and a positional relation change module that changes a positional relation between the first member and the second member. The flow path change module is activated to change the length of the extended flow path by the second flow path defining member, so as to vary the length of the drain socket in the flow direction of the reserved water or cleansing water. The positional relation change module is activated to change the positional relation between the first member and the second member, so as to vary the length of the drain socket in the flow direction of the reserved water or cleansing water. This arrangement allows both the length of the drain socket relative to the floor surface or the wall surface as the reference and the flow path length of the drain socket to be freely adjusted, thus widening the range of application of the drain socket. The same drain socket is preferably applicable to various types of toilets and diverse conditions of sewer by adjusting the height of the drain socket from the floor surface and the flow path of the drain socket.

[0065] It is also preferable that the second flow path defining member is provided with a restriction element that reduces a cross sectional area of the second flow path defining member from an inlet area of the second flow path defining member. This arrangement allows the position of the restriction element to be freely adjusted. Adjusting the position of the restriction element specifies a desired degree of the suction force of reserved water or cleansing water after induction of the siphon action by taking into account the type of the toilet and the conditions of the sewer.

[0066] The present invention may be directed to a toilet with any of the drain sockets discussed above or a toilet connecting with any of the drain sockets discussed above. For example, in the toilet connecting with the drain socket having the variable module, the distance between the floor surface and the end of the drain conduit is adjustable by changing the length of the drain socket relative to the floor surface or the wall surface as the reference. This allows the height of the end of the drain conduit to be relatively freely designed or produced in the design or manufacture of the toilet. In the toilet connecting with the drain socket having the flow path change module, the guide route of reserved water or cleansing water to sewer and the retaining state of reserved water or cleansing water are adjustable by changing the flow path length of the drain socket. This ensures the sufficient cleansing performance of the toilet without requiring any complicated structure.

[0067] The present invention is further directed to a socket flow path extension member that is attached to a drain socket, which connects an end of a drain conduit of a toilet with an external soil pipe, and extends a flow path formed inside the drain socket to a downstream side. At least 2 numerical values representing length of the extended flow path are displayed.

[0068] The socket flow path extension member having the above construction readily specifies a desired length of extension when extending the flow path of the drain socket. Different numerical values corresponding to the types of toilets or installation conditions of the toilet may be given as the at least two numerical values. This enables the flow path in the drain socket to be extended to a desired length.

[0069] At least part of the above objects is attained by a third drain socket that is interposed between a siphon trap of a toilet and a drain conduit outside the toilet and has a socket flow path for leading a flow of cleansing water passing through the siphon trap to the drain conduit. The drain socket is provided with a regulation module disposed in the socket flow path to regulate and increase a flow rate of cleansing water passing through the socket flow path in a terminal stage of a siphon action, which is end of the siphon action induced by a full water level of the siphon trap.

[0070] In the third drain socket of the present invention having the above construction, the flow rate of cleansing water passing through the socket flow path is increased in the terminal stage of the siphon action. This arrangement does not reduce the ratio of the occupation area of the flow of cleansing water to the cross sectional area of the pipeline. The arrangement accordingly prevents invasion of the air from the downstream and extends the effective siphon action. This enhances the suction efficiency of reserved water in the bowl in the terminal stage of the siphon action and the reliability of suction and discharge of floating excrement.

[0071] The terminal stage of the siphon action is specified by the flow rate of cleansing water fed to the toilet for cleansing, the quantity of water reserved in the bowl, and the pipeline diameter of the siphon trap, and is determined according to the elapse of time from the start of the flushing action. The timing of the increase is thus specified according to the elapse of time.

[0072] In accordance with one preferable application of the third drain socket of the present invention, the regulation module includes a supplement unit that supplements the cleansing water passing through the socket flow path with reserved cleansing water in the terminal stage of the siphon action.

[0073] This arrangement increases the flow rate of cleansing water passing through the socket flow path with the supplement of cleansing water to extend the effective siphon action, thus enhancing the suction efficiency of reserved water in the bowl in the terminal stage of the siphon action and the reliability of suction and discharge of floating excrement.

[0074] In the above application, the regulation module may have a plurality of supplement units to supply cleansing water at a plurality of different places. This ensures extension of the effective siphon action with the supplement of cleansing water.

[0075] The drain socket or the siphon trap of the toilet may be provided with a siphon induction mechanism, which temporarily retains the flow of cleansing water and thereby induces the siphon action. The supplement unit of the drain socket may be disposed in the vicinity of the siphon induction mechanism. This arrangement enables supplement of cleansing water in the vicinity of the siphon action-inducing place, thus ensuring the extension of the effective siphon action and enhancing the reliability.

[0076] In accordance with another preferable application, the supplement unit has a reservoir unit that reserves part of cleansing water passing through either one of the socket flow path and the siphon trap, prior to the terminal stage of the siphon action.

[0077] The application enables the supply of cleansing water fed to the toilet for cleansing to be partly used for the supplement of cleansing water without requiring any specific water system for supplement of cleansing water. This arrangement does not undesirably increase the quantity of cleansing water, while simplifying the construction.

[0078] In accordance with still another preferable application, the regulation module has a unit that restricts a flow of cleansing water through the socket flow path before the terminal stage of the siphon action and relieves the restriction in the terminal stage of the siphon action.

[0079] The application relieves the restriction in the terminal stage of the siphon action to increase the flow rate, thus extending the effective siphon action and enhancing the suction efficiency of reserved water in the bowl in the terminal stage of the siphon action. A power-driven device may be applied to relive the restriction. In this case, the device is driven to relieve the restriction, based on the elapse of time since the start of the flushing action.

[0080] The present invention is also directed to a second toilet with a siphon trap, wherein the siphon trap includes: a first descending conduit that is arranged downstream a curved portion; and a second descending conduit that defines a downstream pathway and is connected to a drain conduit outside the toilet to lead cleansing water to the drain conduit. The second descending conduit is provided with a regulation module that regulates and increases a flow rate of cleansing water passing through the second descending conduit in a terminal stage of a siphon action, which is end of the siphon action induced by a full water level of the siphon trap.

[0081] In the second toilet of the present invention, the flow rate of cleansing water passing through the second descending conduit is increased in the terminal stage of the siphon action. The toilet of the above construction thus extends the effective siphon action and enhances the suction efficiency of reserved water in the bowl in the terminal stage of the siphon action and the reliability of suction and discharge of floating excrement.

[0082] The second descending conduit may be constructed separately from the siphon trap including the first descending conduit and be interposed between the first descending conduit and the drain conduit.

[0083] This arrangement advantageously allows application of the existing siphon trap to the pottery toilet body.

[0084] The second descending conduit constructed separately may form or replace any of the drain sockets discussed above.

[0085] The toilet with the siphon trap may be provided with any of the drain sockets discussed above.

[0086] At least part of the objects mentioned above is also attained by a third siphon action-type toilet, which includes a bowl that receives excrement and keeps water therein as reserved water, and a drain conduit that defines a drain flow path, through which a supply of cleansing water fed to the bowl is flown out together with the reserved water. The drain conduit has: a retention module that temporarily retains a flow of cleansing water through the drain flow path and thereby induces a siphon action; and a delay module that is disposed downstream the retention module and lowers a flow velocity of cleansing water when a flow rate or a flow velocity of cleansing water passing through the retention module is not greater than a preset level.

[0087] In the third toilet of the present invention, excrement and cleansing water discharged out of the bowl pass through the drain flow path defined by the drain conduit and are flown out to a drain conduit leading to sewer. The cleansing water flowing in the drain flow path passes through the retention module and the delay module. The retention module temporarily retains the flow of cleansing water through the drain flow path and thereby induces the siphon action. This arrangement causes the cleansing water and the excrement in the bowl to be quickly flown out through the drain conduit.

[0088] In the cleansing process, the flow of cleansing water passing through the retention modules goes to the delay module. The delay module allows direct flow of cleansing water when the cleansing water has a flow rate or flow velocity of greater than a preset level to attain instant discharge, but increases the flow resistance and lowers the flow velocity of cleansing water when the cleansing water has the flow rate or flow velocity of not greater than the preset level. Namely the flow of cleansing water instantly discharges excrement in an initial stage or an intermediate stage of the siphon action, when the cleansing water flown out of the bowl has a high flow velocity. The flow of cleansing water is, on the other hand, delayed and retained in a terminal stage of the siphon action, when the cleansing water has a low flow velocity. This arrangement enables even floating excrement, which requires a relatively long time for discharge, to be discharged from the bowl without failure.

[0089] In accordance with one preferable application of the third toilet of the present invention, the retention module has a restriction element that is protruded from an inner wall of the drain conduit and reduces a flow path area of the drain flow path. The restriction element traps the flow of cleansing water in the drain flow path and thereby induces the siphon action. The retention module may be provided with a separation element that leads cleansing water flown along an inner wall of the drain flow path to be apart from the inner wall. In one preferable embodiment, the separation element is a separation convex that is protruded from an inner wall of the drain flow path. The separation convex changes the flow direction of cleansing water through the drain flow path and instantly induces the siphon action.

[0090] In one preferable embodiment, the delay module may have a delay convex protruded from an inner wall of the drain flow path. The delay convex is designed to receive a flow of cleansing water passing through the separation convex when the cleansing water has a flow velocity or flow rate of not greater than a preset level. This slows down the flow of cleansing water.

[0091] The delay module has a flow direction change sub-module that changes a flow direction of the cleansing water passing through the drain flow path. The flow direction change sub-module makes a flow in a diversity of directions, for example, in a direction perpendicular to an inner wall of the drain flow path, in a circumferential direction of the inner wall, or in a spiral form along the inner wall. One preferable embodiment of the flow direction change sub-module is a guide member that causes the cleansing water passing through the drain flow path to be flown in a spiral form along the inner wall. The guide member makes the spiral flow of cleansing water and thereby extends the total flow time.

[0092] At least one of the retention module and the delay module may be disposed inside the drain conduit integrated with the bowl, or may be separate from the drain conduit. In the latter structure, the drain conduit is formed separately from the bowl and includes a drain socket, which connects a drainage port of the bowl to a drain conduit leading to sewer. The drain socket is provided with the retention module and the separation element. In one preferable embodiment, the drain socket has a socket main body that defines the drain flow path, and the retention module and the separation element are detachably attached to the socket main body. This arrangement facilitates die molding of the retention module and the separation element of even complicated contours.

BRIEF DESCRIPTION OF THE DRAWINGS

[0093]FIG. 1 is a vertical sectional view illustrating a siphon jet action-type toilet 10 in one embodiment of the present invention;

[0094]FIG. 2 illustrates a top face of the toilet 10;

[0095]FIG. 3 illustrates application of the present invention to another toilet having a descending pathway 33 of simple pipeline structure in one modified example;

[0096]FIG. 4 is a sectional view illustrating a drain socket 70 of another modified example, in which a socket main body 71 is integrated with an inner drain conduit socket member 72;

[0097]FIG. 5 is a sectional view illustrating the main part of the drain socket 70 in still another modified example

[0098]FIG. 6 is a sectional view illustrating the main part of the drain socket 70 in another modified example;

[0099]FIG. 7 illustrates the drain socket 70 of still another modified example adopted in a structure that the descending pathway 33 of the trap conduit is off to a drain conduit 90;

[0100]FIG. 8 is a decomposed perspective view illustrating a drain socket joint member applied to a lead drain conduit 90;

[0101]FIG. 9 is a sectional view illustrating the drain socket joint member;

[0102]FIG. 10 is a plan view of the drain socket joint member;

[0103]FIG. 11 is a sectional view illustrating a toilet 110 with a drain socket 120 in a second embodiment of the present invention;

[0104]FIG. 12 shows drain conduits P of four different specifications connecting with the drain socket;

[0105]FIG. 13 shows layout of the drain conduit P in the floor surface FL of the lavatory;

[0106]FIG. 14 is a sectional view illustrating the drain socket 120 of FIG. 11;

[0107]FIG. 15 is a sectional view illustrating the drain socket 120 taken in a direction perpendicular to the longitudinal axis of a toilet body 111;

[0108]FIG. 16 is an enlarged sectional view illustrating the vicinity of a drain conduit joint member 124;

[0109]FIG. 17 is a side view of the drain socket 120;

[0110]FIG. 18 is a bottom view of the drain socket 120;

[0111]FIG. 19 shows a process of setting the drain socket 120;

[0112]FIG. 20 shows a process of installing the toilet with the drain socket 120;

[0113]FIG. 21 shows another process of installing the toilet with the drain socket when the drain conduit is disposed at a different position from that of FIG. 20;

[0114]FIG. 22 is an enlarged sectional view illustrating the vicinity of the drain socket 120;

[0115]FIG. 23 is a sectional view illustrating another drain socket 120B in a third embodiment;

[0116]FIG. 24 is a sectional view illustrating still another drain socket 120C in a fourth embodiment;

[0117]FIG. 25 is a sectional view illustrating another drain socket 120D in a fifth embodiment;

[0118]FIG. 26 is an enlarged sectional view illustrating the vicinity of a restriction element 124Db in the fifth embodiment;

[0119]FIG. 27 illustrates the vicinity of another restriction element 124Ea;

[0120]FIG. 28 is a plan view illustrating the restriction element 124Ea;

[0121]FIG. 29 is a sectional view illustrating the vicinity of another drain socket 120F in a sixth embodiment;

[0122]FIG. 30 shows the positional relationship between a trap drain conduit of a toilet body and the drain socket;

[0123]FIG. 31 is a sectional view illustrating the vicinity of a toilet 210 with a drain socket 220 in a seventh embodiment of the present invention;

[0124]FIG. 32 is an enlarged sectional view illustrating the drain socket 220 shown in FIG. 31;

[0125]FIG. 33 is a sectional view illustrating the drain socket 220 taken in a direction perpendicular to the longitudinal axis of a toilet body 211;

[0126]FIG. 34 is an enlarged sectional view illustrating the vicinity of a drain conduit joint member 224;

[0127]FIG. 35 is a side view of the drain socket 220;

[0128]FIG. 36 is a bottom view of the drain socket 220;

[0129]FIG. 37 shows a process of setting the drain socket 220;

[0130]FIG. 38 shows a process of installing the toilet with the drain socket 220;

[0131]FIG. 39 shows another process of installing the toilet with the drain socket when the drain conduit is disposed at a different position from that of FIG. 38;

[0132]FIG. 40 is a sectional view illustrating a cleansing water retention module 230;

[0133]FIG. 41 is a top view illustrating the cleansing water retention module 230;

[0134]FIG. 42 is a sectional view illustrating a drain socket 220B and a cleansing water retention module 230B in an eighth embodiment;

[0135]FIG. 43 illustrates a cleansing water retention module 230C;

[0136]FIG. 44 illustrates a cleansing water retention module 230D;

[0137]FIG. 45 illustrates a cleansing water retention module 230E;

[0138]FIG. 46 illustrates a cleansing water retention module 230F;

[0139]FIG. 47 illustrates a cleansing water retention module 230G;

[0140]FIG. 48 illustrates a cleansing water retention module 230H;

[0141]FIG. 49 illustrates a cleansing water retention module 230J;

[0142]FIG. 50 illustrates a cleansing water retention module 230K;

[0143]FIG. 51 illustrates a cleansing water retention module 230L;

[0144]FIG. 52 illustrates a cleansing water retention module 230M;

[0145]FIG. 53 is a vertical sectional view illustrating a siphon jet action-type toilet 310 with a drain socket 360 connected thereto in a ninth embodiment of the present invention;

[0146]FIG. 54 shows the detailed structure of the drain socket 360;

[0147]FIG. 55 shows a top face of a base member 380;

[0148]FIG. 56 shows a cross section of an engaging element 382, taken on a centerline C-C in FIG. 54;

[0149]FIG. 57 is a perspective view illustrating the base member 380;

[0150]FIG. 58 shows the front side of the drain socket 360, where four engagement pieces 389 a and 389 p are fitted in lower-most horizontal grooves 382 c and 382 r;

[0151]FIG. 59 shows the drain socket 360 after adjustment of the height of the drain socket 360 from the floor surface FL to 200 mm;

[0152]FIG. 60 is a vertical sectional view illustrating the drain socket 360 adjusted to a height of 200 mm from the floor surface FL and attached to another toilet 510;

[0153]FIG. 61 is a vertical sectional view illustrating connection of a toilet 810 to a drain conduit 8390 via a drain socket 8360 in a tenth embodiment of the present invention;

[0154]FIG. 62 shows an inner drain conduit socket member 372 attached to a different position of a main body member 8371;

[0155]FIG. 63 is a vertical sectional view illustrating connection of a toilet 1310 to a drain conduit 1390 via a drain socket 1360 in an eleventh embodiment of the present invention;

[0156]FIG. 64 shows the appearance of a first cylindrical section 1372 b;

[0157]FIG. 65 shows attachment of a cut inner drain conduit socket member 1372 to a fringe 1379 a;

[0158]FIG. 66 shows a first cylindrical section 2372 b as a modified example;

[0159]FIG. 67 is a vertical sectional view illustrating a siphon jet action-type toilet 410 in a twelfth embodiment of the present invention;

[0160]FIG. 68 shows behaviors of cleansing water passing through a siphon trap and a socket conduit 472;

[0161]FIG. 69 shows a modified structure of a drain socket 470;

[0162]FIG. 70 illustrates a drain socket 1470 in a thirteenth embodiment;

[0163]FIG. 71 shows a drain socket 1470A in a modified example;

[0164]FIG. 72 illustrates a drain socket 2470 in a fourteenth embodiment;

[0165]FIG. 73 is a vertical sectional view illustrating a siphon jet action-type toilet 610 in a fifteenth embodiment of the present invention;

[0166]FIG. 74 shows the top face of the toilet 610;

[0167]FIG. 75 is an enlarged sectional view illustrating the vicinity of the drain socket 670 of FIG. 73;

[0168]FIG. 76 is a perspective view illustrating the partly broken drain socket 670 to show the details of the vicinity of a cleansing water retention module 680;

[0169]FIG. 77 shows a time-based variation in flow rate of cleansing water flown out of a drainage port in a cleansing process;

[0170]FIG. 78 shows initial and middle stages in the cleansing process;

[0171]FIG. 79 shows a terminal stage in the cleansing process; and

[0172]FIG. 80 is a sectional view showing the periphery of a drainage device attached to a prior art toilet.

BEST MODES OF CARRYING OUT THE INVENTION

[0173] In order to clarify the construction and functions of the present invention described above, toilets according to the present invention are discussed below as preferred embodiments. FIG. 1 is a vertical sectional view illustrating a siphon jet action-type toilet 10 in one embodiment (first embodiment) of the present invention. FIG. 2 illustrates a top face of the toilet 10. The siphon jet action-type toilet 10 makes cleansing water ejected from a jet nozzle 22 discussed later to induce the siphon action. Respective constituents of the toilet 10 are discussed below with reference to FIGS. 1 and 2.

[0174] Referring to FIG. 1, the toilet 10 has a bowl 20 to receive excrement therein. A peripheral wall of the bowl 20 has a water-submerged surface 23 that is in contact with reserved water RW even in a non-cleansing time of the toilet 10 and an exposed surface 24 that is not in contact with the reserved water RW in the non-cleansing time of the toilet 10.

[0175] Referring to FIG. 2, the jet nozzle 22 is connected to a jet supply nozzle 45, which is an inlet of water ejected from the jet nozzle 22, via a jet supply conduit 46 curved inside the toilet. The jet nozzle 22 is located to substantially face a drainage port 25 across a recess 26 as shown in FIG. 1. Energy of cleansing water is thus transmitted to a drainage mechanism of and after the drainage port 25 without any significant waste. This leads to instant induction of the siphon action.

[0176] The toilet 10 is provided with a mechanism for supplying water to the bowl 20 (hereinafter referred to as the supply mechanism) and a mechanism for discharging excrement in the bowl 20 toward a drain conduit 90 (hereinafter referred to as the drainage mechanism).

[0177] The supply mechanism is discussed first. A cleansing water supply aperture 40, which is a hole connecting with a water supply pipe SL of a water tank WT, is provided behind the toilet 10. A cleansing water supply conduit 41, which defines a flow path of cleansing water led from the water tank WT, is disposed inside the toilet 10 along a passage from the cleansing water supply aperture 40 towards the bowl 20. The cleansing water supply conduit 41 divisionally forms a retention space 41 a as a space interposed between the jet supply conduit 46 for ejecting a jet of cleansing water towards the bowl and a lower end of a drain conduit of the water tank WT. In response to each flushing action, cleansing water discharged from the drain conduit is flown into the retention space 41 a and passes through the jet supply conduit 46 and a branch hole 42 discussed later to rim supply conduits 43. The retention space 41 a functions as an air gap without cleansing water during the non-cleansing time.

[0178] Water (cleansing water) kept in the tank is pressed by free fall and is fed at once to the cleansing water supply conduit 41. The retention space 41 a, the lower oblique division of the cleansing water supply conduit 41, is filled with water after start of each flushing action. Part of the cleansing water is supplied from the branch hole 42 to the rim supply conduits 43. The flow of cleansing water supplied to the rim supply conduits 43 is ejected from water outlets 44 (see FIG. 2) formed in a rear face of a rim member 21.

[0179] As shown in FIG. 2, there are five different types of water outlets 44 having various shapes, that is, a large aperture 44 a of 7 mm in diameter, medium apertures 44 b of 4 mm in diameter, small apertures 44 c of 3 mm in diameter, and quasi rectangular slots 44 d and 44 e, provided on the rear face of the rim member 21. The water outlets 44 are typically formed in the course of production of the rim member 21. A distributor with water outlets may otherwise be attached to the rear face of the rim member 21.

[0180] A total opening area SA of the water outlets 44, that is, the large aperture 44 a, the medium apertures 44 b, the small apertures 44 c, and the slots 44 d and 44 e, is calculated as summation of the product of the area of each water outlet and its number. An area ratio (SH/SA) of an effective pathway area (opening area for leading out cleansing water) SH of the branch hole 42, which leads the flow of cleansing water to the respective water outlets, to the total opening area SA is set equal to approximately 1.23. The flow of cleansing water fed to the rim supply conduits 43 is regulated by the opening of the branch hole 42. The flow rate is regulated in a substantially linear relation corresponding to the area ratio. A variation in area ratio results in a significantly large variation in flow rate. The presence of the branch hole 42 thus enables the flow rate to be regulated effectively. This arrangement also ensures easy setting of the flow rate without any trial and error in design and inspection.

[0181] Among the water outlets 44, the slots 44 d and 44 e are provided to give a swirl force to the cleansing water ejected out of the water outlets 44. The cleansing water pressed forward in the toilet 10 is led into the left and right rim supply conduits 43, is distributed according to the opening diameters of the water outlets 44 and the pressing force of cleansing water, and is ejected out of the respective water outlets 44 a through 44 e. The cleansing water of the large pressing force is ejected from the slot 44 d, which is formed on the right back side close to the branch hole 42 in the rear face of the rim member 21, toward the exposed surface 24 on the slightly left side in the front portion of the toilet. A large quantity of the clockwise flow of cleansing water through the rim supply conduits 43 is ejected from the slot 44 e, which is formed on the slightly right side position in the front portion of the toilet 10, toward the exposed surface 24 in the rear left portion of the toilet 10. The cleansing water ejected from the slots 44 d and 44 e makes a main stream and gives the clockwise swirling force to the cleansing water ejected out of the water outlets 44. The swirling force is transferred to reserved water RW in the bowl 20. This makes a clockwise swirl flow of water in the bowl 20.

[0182] The above description regards one of the methods of giving the swirl force to the cleansing water ejected out of the water outlets 44. Any of the other methods is also applicable for the same purpose. One applicable method designs some of the water outlets 44 to have a certain angle in the swirling direction. Another method makes the flow of water in a single direction in the rim supply conduits 43. In the structure of the first embodiment according to the present invention, cleansing water is ejected from the rim as discussed above. One possible modification makes simple free fall of cleansing water from the rim. Another modification makes no ejection or fall of cleansing water from the rim.

[0183] The cleansing water reaching the retention space 41 a goes into the jet supply nozzle 45, which is formed in the side wall of the retention space 41 a. This leads to supply of cleansing water into the jet supply conduit 46. The cleansing water supplied to the jet supply conduit 46 is jetted out of the jet nozzle 22. When the retention space 41 a is filled with the new supply of cleansing water, the cleansing water is led to the rim supply conduits 43 via the branch hole 42 and is ejected out of the water outlets 44 of the rim.

[0184] The distribution into the total flow rate of water ejected out of the water outlets 44 and the flow rate of water jetted out of the jet nozzle 22 is set arbitrarily by regulating the effective pathway area (opening area for leading out cleansing water) SH.

[0185] The drainage mechanism has the construction discussed below. As shown in FIG. 1, a connection pathway 31 that is curved in an oblique upward direction from the drainage port 25, an ascending pathway 32 that is extended in the curved direction of the connection pathway 31 and is then curved in a lateral direction, and a descending pathway 33 that is curved in the lateral direction and subsequently in a downward direction are formed as a flow path (trap) of water and excrement and are disposed after the drainage port 25, which is formed behind the recess 26 working as the excrement reservoir. The connection pathway 31 and the ascending pathway 32 correspond to the ascending conduit of the present invention.

[0186] The descending pathway 33 includes an expanded section 33 a having a greater pipeline diameter and a tapered end 33 b having a narrower opening area than that of the expanded section 33 a. The expanded section 33 a and the tapered end 33 b of the descending pathway 33 function to temporarily retain the flow of cleansing water, so that the descending pathway 33 induces the siphon action. The end of the descending pathway 33 is connected to the drain conduit 90, which rises upward from a floor surface FL of a lavatory at the installation position of the toilet, via a resin drain socket 70.

[0187] The distance from the rear end of the toilet 10 illustrated in FIG. 1 to the center of the drain conduit 90 is 180 mm, and the distance from the rear end of the water tank WT attached to the toilet 10 to the center of the drain conduit 90 is 190 mm. Namely arrangement of the drain conduit 90 rising upward to a position of about 200 mm apart from the wall of the lavatory enables the assembly of the toilet 10 and the water tank WT to be installed with a clearance of 10 mm between the rear face of the water tank WT and the wall of the lavatory. Installation of the assembly of the toilet 10 and the water tank WT under such conditions allows the layout of the drain conduit 90 at a position close to the construction wall. This layout shortens the distance from the drain conduit 90 to a pipe space and ensures smooth transport of excrement. The distance may be 200 mm or less when no consideration is given to the clearance from the wall of the lavatory.

[0188] The flow paths discussed above are formed integrally with the toilet 10 made of pottery by utilizing a plaster or resin mold, although the flow paths may be made of a different material separately from the toilet 10. For example, all or part of the flow paths may be made of another material like resin and connected to the drainage port 25.

[0189] The drain socket 70 includes a socket main body 71 that is positioned above the floor surface FL of the lavatory and is fixed to the floor surface FL of the lavatory, for example, with a bolt, and an inner drain conduit socket member 72 that is attached to be located inside the drain conduit 90. The socket main body 71 has a descending pathway fitting element 71 a, which receives a lower end of the descending pathway 33 fitted therein, and a first water pipe 73 disposed below the fitting element 71 a. The first water pipe 73 has a diameter substantially equal to the diameter of the lower end of the descending pathway 33. The socket main body 71 has a drain conduit fitting element 74, which receives the upper end of the drain conduit 90 extending upward. The fitting of the drain conduit 90 in the drain conduit fitting element 74 positions the drain socket 70 relative to the drain conduit 90. Location of the lower end of the first water pipe 73 below the upper end of the drain conduit 90 effectively prevents the flow of cleansing water through the first water pipe 73 from leaking out of the upper end of the drain conduit 90.

[0190] The inner drain conduit socket member 72 has a first tapered cylindrical section 72 b with an upper jaw end 72 a, and a second straight cylindrical section 72 c extending from the first cylindrical section 72 b. Since the first cylindrical section 72 b is tapered, the inner drain conduit socket member 72 is fitted in and attached to the drain conduit 90 regardless of a slight variation in diameter of the drain conduit 90, such that the jaw end 72 a is in contact with or slightly apart from the upper end of the drain conduit 90. Application of a sealing sheet like a rubber sheet to the space between the upper outer circumferential part of the first cylindrical section 72 b and the rear face of the jaw end 72 a in the inner drain conduit socket member 72 desirably seals the upper opening of the drain conduit 90 and attains the water tightness of the pipeline.

[0191] The inner drain conduit socket member 72 attached to the drain conduit 90 has an extended socket section 75, which is located below the first water pipe 73 and has a greater diameter than the diameter of the first water pipe 73, and a tapered conduit section 76, which is located below the extended socket section 75 and has a diameter substantially equal to the diameter of the first water pipe 73. The extended socket section 75 and the tapered conduit section 76 are positioned below the floor surface FL of the lavatory to form a drainage pipeline of cleansing water. The extended socket section 75 and the tapered conduit section 76 positioned below the floor surface FL of the lavatory function to temporarily keep the flow of cleansing water and thereby induce the siphon action.

[0192] The socket main body 71 and the inner drain conduit socket member 72 of the drain socket 70 are both resin molded objects formed separately from the toilet 10 or more specifically from the descending pathway 33, although they may be integrated with the descending pathway 33. In the latter structure, a pipe like the first water pipe 73 is connected to the expanded section 33 a across the tapered end 33 b, and an extended section like the extended socket section 75 and a conduit like the tapered conduit section 76 communicate with the lower end of the pie and are made of the same material as that of the descending pathway 33. The socket main body 71 and the inner drain conduit socket member 72 of the drain socket 70 as the resin molded objects may be made of the same vinyl chloride resin as the material of the drain conduit 90. Any of other diverse resins, such as ABS resin, PP (polypropylene), PE (polyethylene), PPS (polyphenylene sulfide), MA (acrylic resin), and POM (polyacetal) is also applicable.

[0193] In this structure, the inner drain conduit socket member 72 may be separate from the socket main body 71 and thus be attachable independently to the drain conduit 90. The drain conduit 90 itself then induces the siphon action.

[0194] In the toilet 10 with the drain socket 70 attached thereto, the descending conduit for drainage of cleansing water is formed to be extended downward from the floor surface FL of the lavatory. The expanded section and the tapered section for inducing the siphon action are formed in the extension from the floor surface FL of the lavatory.

[0195] Referring again to FIG. 1, in the toilet 10 before a flushing action, the reserved water RW in the connection pathway 31, the ascending pathway 32, and the bowl 20 reaches the standard height of water level WL. The reserved water RW effectively prevents a reverse flow of offensive odor and invasion of vermin from the drainage mechanism to the bowl 20. The structure of the first embodiment ensures a wide area of retained water as 185 mm in width×225 mm in length, while reducing the quantity of the reserved water RW. This arrangement effectively prevents adhesion of excrement to the bowl 20 and effusion of offensive odor from the exposed surface 24.

[0196] The reserved water RW includes water kept in the bowl 20 before the drainage port 25 (hereinafter this water is referred to as the bowl storage water or the sealing water), water kept in the connection pathway 31 and the ascending pathway 32 after the drainage port 25 (hereinafter this water is referred to as the flow path storage water), and water kept in the lower portion of the retention space 41 a and the jet supply conduit 46 of the toilet 10 (hereinafter this water is referred to as the jet storage water). As shown in FIG. 1, the flow path storage water is kept at only one place along the connection pathway 31 or the ascending pathway 32, out of the flow path of sanitary sewage including the connection pathway 31, the ascending pathway 32, and the descending pathway 33. Here the ‘sanitary sewage’ means dirt water mixed with excrement like stool and urine and paper.

[0197] The water level WL generally depends upon the height of a weir 34, which is the highest position of the lower inner wall of the ascending pathway 32. The lower portion of the retention space 41 a, the jet supply nozzle 45, and the jet supply conduit 46 are located below the weir 34 in the toilet 10 as shown in FIG. 1. In the stationary state of the toilet 10, the jet storage water is kept at the above water level in the lower portion of the retention space 41 a and the jet supply conduit 46. The lowered height of the weir 34 lowers the water level of the reserved water RW and decreases the total quantity of the bowl storage water, the flow path storage water, and the jet storage water.

[0198] The following describes the process of discharging the sanitary sewage and excrement by means of the drainage mechanism having the above construction. A release of cleansing water from the water tank WT first flows into the retention space 41 a. The potential energy of the released cleansing water works as kinetic energy and causes the jet storage water in the jet supply conduit 46 to flow into the bowl storage water (sealing water) in the bowl 20. This starts a jet of cleansing water from the jet nozzle 22 toward the trap described above. While the release of cleansing water continues, the released cleansing water is continuously jetted from the jet nozzle 22 by means of its potential energy. In the initial stage of the water jet action, the retention space 41 a is filled with the new release of cleansing water. In the subsequent stage, the release of cleansing water passes through the branch hole 42 and is ejected out of the water outlets 44.

[0199] When the cleansing water is ejected out to the bowl 20, the water level in the ascending pathway 32 rises and the water reaches its full level at the curved joint portion of the ascending pathway 32 and the descending pathway 33 (hereinafter simply referred to as the curved portion). The flow of cleansing water then passes through the descending pathway 33, and is temporarily retained in the expanded section 33 a on the lower end of the descending pathway 33 as well as in the extended socket section 75 and the tapered conduit section 76, which are located below the floor surface FL of the lavatory. There is a pressure difference between the temporarily retained cleansing water and the reserved water in the bowl 20. This pressure difference generates a downward pulling force, which causes the excrement together with the cleansing water (sanitary sewage) in the ascending pathway 32 and the connection pathway 31 and the cleansing water (sanitary sewage) in the bowl to be vigorously led into the drain conduit 90. This process induces the siphon action.

[0200] In the siphon jet action-type toilet 10 of the first embodiment thus constructed, the siphon action is induced not only by the expanded section 33 a and the tapered end 33 b on the lower end of the descending pathway 33 but by the extended socket section 75 and the tapered conduit section 76 of the drain socket 70 located lower than the floor surface FL of the lavatory. This arrangement gives the advantages discussed below.

[0201] The siphon action is induced by the two different places, that is, the lower end of the descending pathway 33 and the drain socket 70. This arrangement enhances the sucking force of reserved water in the bowl 20 and the suction efficiency by means of the siphon action.

[0202] The extended socket section 75 and the tapered conduit section 76 of the drain socket 70 formed for the purpose of inducting the siphon action are located below the floor surface FL of the lavatory. This increases the head difference in the process of inducing the siphon action. This further enhances the sucking force of reserved water and the suction efficiency by means of the siphon action. The lower end of the pipeline for drainage of cleansing water forms the tapered conduit section 76, and the extended socket section 75 is provided in the vicinity of this lower end of the pipeline. This arrangement ensures a greater head difference in the process of inducing the siphon action and thereby effectively enhances the sucking force of reserved water and the suction efficiency.

[0203] The tapered end 33 b formed on the lower end of the descending pathway 33 and the tapered conduit section 76 of the drain socket 70 are the tapered parts of the pipeline functioning as the siphon action-inducing parts. These tapered parts are arranged vertically along the descending pathway. This arrangement ensures temporary retention of the flow of cleansing water and effectively induces the siphon action to enhance the sucking force of reserved water and the suction efficiency. The tapered conduit section 76 of the drain socket 70 extends by a certain length (about 40 mm) in the direction of the pipeline. Such extension interferes with the direct flow of cleansing water and elongates the time of water retention. This lengthens the siphon action induction time and thus ensures the effective enhancement of the sucking force of reserved water and the suction efficiency.

[0204] The drain socket 70, which is separate from the toilet 10, is used as the siphon action-inducing part located below the floor surface FL of the lavatory. The toilet 10 is accordingly made of pottery as the conventional toilet and is not required to have any extended part from its bottom face. This arrangement does not require production of a new mold and is thus advantageous in manufacture. This arrangement also facilitates installation, transport, and packing of the toilet. Since the drain socket 70 forms the siphon action-inducing part below the floor surface FL of the lavatory, the existing toilet 10 is advantageously applicable.

[0205] The siphon action-inducing part of the drain socket 70 is formed below the floor surface FL of the lavatory by attaching the inner drain conduit socket member 72, which is separate from the socket main body 71 of the drain socket 70, to the existing drain conduit 90. This arrangement does not require relocation of the drain conduit. The toilet 10 of the first embodiment is thus readily installed at the time of reforming the lavatory.

[0206] Some examples of possible modification are discussed below. The first embodiment regards the toilet in which the descending pathway 33 itself induces the siphon action by the function of the expanded section 33 a on its lower end. The technique of the present invention is, however, also applicable to another toilet, in which the descending pathway 33 forms a simple pipeline and is not provided with the siphon action-inducing part. FIG. 3 illustrates application of the present invention to another toilet having the descending pathway 33 of simple pipeline structure in one modified example. In the modified example, the extended socket section 75 and the tapered conduit section 76 located below the floor surface FL of the lavatory induces the siphon action by taking advantage of a large head difference, thus effectively enhancing the sucking force of reserved water and the suction efficiency. In this modified example, setting a smaller diameter to the first water pipe 73 defined by the socket main body 71 than the diameter of the pipeline of the descending pathway 33 before the first water pipe 73 makes the first water pipe 73 function as the tapered portion for inducing the siphon action. This arrangement desirably ensures induction of the siphon action at a plurality of different places.

[0207]FIG. 4 is a sectional view illustrating the drain socket 70 of another modified example, in which the socket main body 71 is integrated with the inner drain conduit socket member 72. In the drain socket 70 of this modified example, the socket main body 71 defines the first water pipe 73 below the descending pathway 33, while the inner drain conduit socket member 72 defines the extended socket section 75 of a greater diameter connecting with the first water pipe 73 and the tapered conduit section 76 having a diameter substantially equal to the diameter of the first water pipe 73. In the drain socket 70 of this modified example, the extended socket section 75 and the tapered conduit section 76 function as the siphon action-inducing part located below the floor surface FL of the lavatory. In the modified example, the inner drain conduit socket member 72 is a blow molded object having a swelled middle portion, and is screwed to the lower end of the first water pipe 73 defined by the socket main body 71 at the threaded part formed in the inner circumference of the upper opening. The drain socket 70 of this modified example also induces the siphon action by taking advantage of a large head difference, thus effectively enhancing the sucking force of reserved water and the suction efficiency. The drain socket 70 is an integral body in this modified example and thereby simplifies attachment to the drain conduit 90.

[0208]FIG. 5 is a sectional view illustrating the main part of the drain socket 70 in still another modified example. As illustrated, in this modified example, a sealing member 77 is applied on the descending pathway fitting element 71 a, which receives the lower end of the descending pathway 33 fitted therein. The sealing member 77 is made of an elastic material like rubber. In response to insertion of the descending pathway 33, a tapered inner circumference of the sealing member 77 is stretched to be in close contact with the outer circumference of the descending pathway 33 to attain sealing. The structure of this modified example ensures water tightness at the lower end of the descending pathway, so as to prevent leakage of cleansing water and excrement from the pipeline. The drain socket 70 is positioned relative to the descending pathway 33 via the sealing member 77.

[0209]FIG. 6 is a sectional view illustrating the main part of the drain socket 70 in another modified example. In this modified example, the drain conduit 90 is not protruded upward from the floor surface FL of the lavatory. As illustrated, sealing members 78, for example, disc rubber sheets, are applied on the upper and lower faces of the jaw end 72 a of the inner drain conduit socket member 72, and the inner drain conduit socket member 72 is then attached to the drain conduit 90. The socket main body 71 is fixed to the floor surface FL of the lavatory in such a manner that a sealing wall 73 a extending downward to surround the first water pipe 73 defined by the socket main body 71 comes into contact with the sealing member 78 on the upper face of the jaw end 72 a to attain sealing. In the structure of this modified example, even when the drain conduit 90 is not extended from the floor surface FL of the lavatory, the siphon action-inducing part is provided below the floor surface FL of the lavatory to exert the effects discussed above. The sealing members 78 ensure the water tightness of the drain conduit 90 and effectively prevent leakage of cleansing water and excrement from the pipeline.

[0210] There are other possible modifications of the first embodiment discussed above.

[0211] For example, in the structure of the first tank, a low tank connecting with the toilet is applied for the water tank. A diversity of tanks other than the low tank, for example, corner and front installation tanks that are connected to the toilet via a wash pipe and located at the wall of the lavatory, may be applicable for the water tank. In such cases, the water tank may be a high tank located at a high position.

[0212] The above description regards application of the technique of the present invention to the siphon jet action-type toilet 10 and the siphon action-type toilet. The technique of the present invention is also applicable to combinations of these toilets with other devices and members. One application is a wash down-type toilet that utilizes the force of cleansing water supplied to the toilet and washes down excrement in the bowl of the toilet and dirt water or sanitary sewage including excrement. Other applications include sanitary cleansing appliances with the functional toilet seat to attain diverse functions like personal cleansing and heating, lavatory furniture including lavatory cabinets and wash basins, and lavatories including structural materials, like wall materials, floor materials, and ceiling materials.

[0213] In the drain socket 70 of the above embodiment, the descending pathway 33 is directly opposite to the drain conduit 90. The technique of the present invention is also applicable to another structure in which the descending pathway 33 is located off to the drain conduit 90. FIG. 7 illustrates the drain socket 70 of such structure in still another modified example. The drain socket 70 of this modified example has the descending pathway fitting element 71 a that receives the lower end of the descending pathway 33 fitted therein and is eccentric to the first water pipe 73, the extended socket section 75, and the tapered conduit section 76 located inside the drain conduit 90. The socket main body 71 is curved or bent according to such positional deviation. Even when the descending pathway 33 is off to the position of the drain conduit 90, this arrangement enables the descending pathway 33 to be connected to the drain conduit 90 via the drain socket 70 and ensures induction of the siphon action by means of the first water pipe 73, the extended socket section 75, and the tapered conduit section 76 in the drain socket.

[0214] The present invention is also applicable to the lead drain conduit 90. FIG. 8 is a decomposed perspective view illustrating a drain socket joint member applied to the lead drain conduit 90. FIG. 9 is a sectional view illustrating the drain socket joint member. FIG. 10 is a plan view of the drain socket joint member.

[0215] As shown in these drawings, in the case of the lead drain conduit 90, a metal flange 171 is fixed to the floor surface FL of the lavatory with screws 172, while the drain conduit 90 is protruded upward. The protrusion of the drain conduit 90 from the floor surface FL of the lavatory is approximately 15 mm. The opening of the drain conduit 90 is extended along a tapered slope 179 of the metal flange 171. A tapered P seal gasket 173 is placed to fit the tapered extended opening of the drain conduit 90, is pressed by an adaptor 174, and is fixed to the metal flange 171 with bolts 175. The drain socket 70 discussed above is then fixed to the upper cylindrical part of the fixed adaptor 174. Even in the case of the lead drain conduit 90, the arrangement of this modified example enables the descending pathway 33 to be connected to the drain conduit 90 via the drain socket 70 and ensures induction of the siphon action by means of the first water pipe 73, the extended socket section 75, and the tapered conduit section 76 in the drain socket.

[0216] Other embodiments are discussed below.

[0217]FIG. 11 is a sectional view illustrating a toilet 110 with a drain socket 120 in a second embodiment of the present invention. The toilet 110 has a pottery toilet body 111 including a bowl 111 a integrated with a trap drain conduit 111 b, a resin drain socket 120, and a water tank. The drain socket 120 connects a drainage port 116 of the toilet body 111 to a drain conduit P protruded from the floor surface FL.

[0218] Referring to FIG. 12, the drain conduit P disposed in the floor surface FL of the lavatory follows any of four specifications as combinations of two outer diameters D1 and D2 and two wall thicknesses t1 and t2. A drain conduit PA has the outer diameter D1 and the wall thickness t1. A drain conduit PB has the outer diameter D1 and the wall thickness t2. A drain conduit PC has the outer diameter D2 and the wall thickness t1. A drain conduit PD has the outer diameter D2 and the wall thickness t2. Here the outer diameters and the wall thicknesses satisfy the relations of D1<D2 and t1<t2. FIG. 13 shows layout of the drain conduit P in the floor surface FL of the lavatory. As shown in FIG. 13, the distance between the drain conduit P(PA) and a front wall WF of the lavatory is not fixed, but the drain conduit P(PA) is installed at different distances L1 (120 mm) and L2 (200 mm) according to the building layout and other conditions. The drain socket 120 is applicable to the four different drain conduits P and the two rough-in dimensions. The drain socket 120 is discussed below in detail.

[0219]FIG. 14 is a sectional view illustrating the drain socket 120 of FIG. 11. FIG. 15 is a sectional view illustrating the drain socket 120 taken in a direction perpendicular to the longitudinal axis of the toilet body 11. As shown in FIGS. 14 and 15, the drain socket 120 includes a toilet joint member 121, a connection conduit 123, a drain conduit joint member 124, a socket fixation member 128 (see FIG. 17), and toilet fixation members 129 (see FIG. 15), which are integrally made of a resin.

[0220] The toilet joint member 121 has a sealing member 122 to seal the outlet end of the trap drain conduit 111 b. The outlet end of the trap drain conduit 111 b is inserted into an opening 122 a of the sealing member 122 to attain sealing and connect the drainage port 116 of the trap drain conduit 111 b to a flow inlet 121 a.

[0221] The toilet joint member 121 and the connection conduit 123 define a socket flow path 123 a, which connects the flow inlet 121 a with a flow outlet 124 a in an eccentric manner. An eccentric distance La of the connection conduit 123 is set to satisfy the relation of La=(L2−L1)/2. A step 123 b is formed above the connection conduit 123 at a position between the connection conduit 123 and the toilet joint member 121. The socket flow path 123 a is designed to create a turbulent flow when the cleansing water hits against the step 123 b, thereby leading to retention of the flow of cleansing water.

[0222] The drain conduit joint member 124 has an outflow cylindrical member 125 with the flow outlet 124 a, as well as a first cylindrical joint element 126 and a second cylindrical joint element 127, which are concentric with the flow outlet 124 a. The outflow cylindrical member 125 is inserted into the drain conduit P led to the sewer, so as to prevent leakage of cleansing water.

[0223] A restriction element 124 b working for area reduction is formed in the middle of the outflow cylindrical member 125. The flow path of the restriction element 124 b is concentric with the socket flow path 123 a of the outflow cylindrical member 125 but has a narrower flow passage area. The abrupt reduction of the flow passage area of the outflow cylindrical member 125 generates the instant siphon action. The restriction element 124 b is formed integrally with the outflow cylindrical member 125 by injection molding.

[0224]FIG. 16 is an enlarged sectional view illustrating the vicinity of the drain conduit joint member 124. Referring to FIG. 16, the first cylindrical joint element 126 and the second cylindrical joint element 127 are cylindrical bodies used to alternatively connect with the drain conduits P of the different outer diameters D1 and D2 (see FIG. 12). A gap d1 between the outflow cylindrical member 125 and the first cylindrical joint element 126 and a gap d2 between the first cylindrical joint element 126 and the second cylindrical joint element 127 are designed to be greater than the wall thickness t2 of the drain conduit P. These gaps d1 and d2 can receive the drain conduits P of the different wall thicknesses t1 and t2 inserted therein. The connection surface of the first cylindrical joint element 126 or the second cylindrical joint element 127 is bonded to the outer circumferential face of the drain conduit P fitted therein via an adhesive.

[0225] The specific structure discussed below facilitates the bonding work. The first cylindrical joint element 126 is formed to be protruded downward from the outflow cylindrical member 125, whereas the second cylindrical joint element 127 is formed to be protruded downward from the first cylindrical joint element 126. Namely the inner cylinder is shorter than the outer cylinder. This arrangement gives a space for the bonding work and assures smooth application of the adhesive on the connection surface of the first cylindrical joint element 126 or the connection surface of the second cylindrical joint element 127, thereby facilitating the bonding work.

[0226]FIG. 17 is a side view of the drain socket 120. FIG. 18 is a bottom view of the drain socket 120. As shown in FIGS. 17 and 18, the socket fixation member 128 is formed integrally with the bottom of the drain socket 120. The socket fixation member 128 is a site functioning to fix the drain socket 120 to the floor surface FL. The socket fixation member 128 includes a socket fixation leg 128 d around the outer circumference of the second cylindrical joint element 127, and a quasi-quadrangular flat plate 128 a extending from the socket fixation leg 128 d in the horizontal direction. The drain socket 120 is fixed to the floor surface FL by means of screws 128 c via four tapped holes 128 b formed in the flat plate 128 a.

[0227] Referring back to FIG. 15, the toilet fixation members 129, 129 are formed on the side of the drain socket 120. The toilet fixation members 129, 129 are a site functioning to fix the toilet body 111 above the drain socket 120. The toilet fixation members 129, 129 have screw fixation elements 129 a, 129 a on the respective upper faces thereof. The screw fixation elements 129 a, 129 a are formed to be symmetrical both about the longitudinal axis of the toilet body 111 and about the axis perpendicular to the longitudinal axis. Even in the case where the orientation of the drain socket 120 is front side back, the screw fixation elements 129 a, 129 a are placed to face socket fixation elements 111 d of the toilet body 111.

[0228] The following describes the installation process of the toilet 110. In a first example, the toilet body 111 is installed with the drain socket 120 when the drain conduit PA shown in FIG. 12(A) is disposed at the distance L1 (120 mm) shown in FIG. 13(A).

[0229]FIG. 19 shows a process of setting the drain socket 120. The drain conduit P is cut at a predetermined height (for example, 60 mm) from the floor level. The procedure then checks the front-back orientation of the drain socket 120, adjusts the centerline of the drain socket 120 with the imaginary installation centerline of the toilet body 111, inserts the first cylindrical joint element 126 of the drain socket 120 into the drain conduit P, and tentatively positions the drain socket 120 as shown in FIG. 20. The drain socket 120 is tentatively laid to make the toilet joint member 121 face front. The procedure then utilizes the tapped holes 128 b of the socket fixation member 128 (see FIGS. 17 and 18) to form prepared holes in the floor surface FL.

[0230] The procedure detaches the drain socket 120 from the floor surface FL and applies the adhesive on the connection surface of the first cylindrical joint element 126 of the drain socket 120 and the outer circumferential face of the drain conduit P. The first cylindrical joint element 126 is then returned to the tentatively positioned place and fitted in the drain conduit P. The first cylindrical joint element 126 is accordingly bonded to the drain conduit P via the adhesive as shown in FIG. 14. The drain socket 120 is fixed to the floor surface FL by means of the screws in the four tapped holes 128 b formed in the socket fixation member 128.

[0231] The procedure subsequently positions the drainage port 116 of the toilet body 111 at the flow inlet 121 a of the toilet joint member 121 of the drain socket 120 as shown in FIG. 15, and lays the toilet body 111 on the floor surface FL. This causes the drainage port 116 to be inserted through the flow inlet 121 a of the toilet joint member 121 and sealed with the sealing member 122. Insertion of screws 129 b, 129 b through the socket fixation elements 111 d of the toilet body 111 and the toilet fixation members 129, 129 fixes the toilet body 111 to the drain socket 120.

[0232] In a second example, the drain socket 120 is connected when the drain conduit PA is disposed at the distance L2 (200 mm) from the front wall WF of the lavatory as shown in FIG. 13(B). This process is identical with the process of the first example, except that the orientation of the drain socket 120 is front side back. The procedure of the second example disposes the drain socket 120 to make the toilet joint member 121 face the front wall WF as shown in FIG. 21. When the drain conduit P is disposed at the different positions, the toilet body 111 is installed at the identical position expressed by (L1+L2)/2 as the distance between the front wall WF and the flow inlet 121 a by simply changing the orientation of the drain socket 120.

[0233] When the drain conduit P is disposed at the different positions, the structure of this embodiment enables the toilet body 111 to be installed at the identical position in the lavatory by simply changing the orientation of the drain socket 120. It is accordingly not necessary to provide different drain sockets 120 corresponding to the layout positions of the drain conduit P.

[0234] In a third example, the toilet body 111 is installed to the drain conduit P of a different outer diameter. The process with regard to the drain conduit PC or the drain conduit PD of the outer diameter D2 shown in FIG. 12(C) or 12(D) is identical with either of the above processes, except that the adhesive is applied on the connection surface of the second cylindrical joint element 127 of the drain socket 120 shown in FIG. 14. The same drain socket 120 is applicable with a change of the adhesive application face corresponding to the outer diameter of the drain conduits PC and PD. The gap d1 between the outflow cylindrical member 125 and the first cylindrical joint element 126 and the gap d2 between the first cylindrical joint element 126 and the second cylindrical joint element 127 are greater than the wall thickness t2 of the drain conduits PB and PD as shown in FIG. 16. The same drain socket 120 is thus connectable with the thicker drain conduit P having the wall thickness t2.

[0235] The same drain socket 120 is applicable to the diverse drain conduits P having the different outer diameters, wall thicknesses, and layout positions as shown in FIGS. 12 and 13 under the same installation conditions by adequately selecting the orientation and the adhesive application face. The drain socket 120 accordingly has the excellent workability.

[0236] The drain socket 120 has the construction discussed below to ensure the instant siphon action. FIG. 22 is an enlarged sectional view illustrating the vicinity of the drain socket 120.

[0237] The drain socket 120 has the step 123 b formed between the toilet joint member 121 and the connection conduit 123. The cleansing water hits against the step 123 b and changes its flow direction to form a water film, which effectively delays the flow of cleansing water and induces the siphon action. The step 123 b is formed by the eccentric layout of the socket flow path 123 a to the flow inlet 121 a and the flow outlet 124 a.

[0238] The restriction element 124 b is formed at the flow outlet 124 a of the drain socket 120. The restriction element 124 b enhances the delay effect of the flow of cleansing water in the vicinity of the flow outlet 124 a. The combined effects of the restriction element 124 b with the step 123 b ensure the instant and effective siphon action.

[0239] The restriction element 124 b is formed integrally with the drain socket 120 by injection molding of a resin. The restriction element 124 b is not required to be attached to the drain conduit P unlike the prior art technique, and is not shifted by water pressure during drainage. This arrangement accordingly ensures the excellent workability and the effective siphon action.

[0240] The embodiment discussed above thus exerts the functions and effects discussed below.

[0241] (1) The drain socket 120 is screwed to the floor surface FL by means of the socket fixation member 128. This assures the secure joint of the drain socket 120 with the drain conduit P.

[0242] (2) The drain conduit P is bonded to either the first cylindrical joint element 126 or the second cylindrical joint element 127 of the drain socket 120 via the adhesive. This arrangement ensures the secure joint and effectively prevents water leakage in the case of back flow.

[0243] (3) The toilet body 111 is screwed and fixed at the toilet fixation members 129. This ensures secure fixation. The fixation position at the rear of the toilet body 111 is located above the floor surface FL. This facilitates cleansing.

[0244] (4) The outflow cylindrical member 125 is provided in the inner-most circumference of the drain socket 120, so that the flow of cleansing water is all led into the drain conduit P. This arrangement effectively prevents water leakage from the joint of the drain conduit P with either the first cylindrical joint element 126 or the second cylindrical joint element 127.

[0245]FIG. 23 is a sectional view illustrating another drain socket 120B in a third embodiment. The drain socket 120B shown in FIG. 23 includes a connection conduit 123B that defines an inclined socket flow path 123Ba, which connects a toilet joint member 121B with an outflow cylindrical member 125B. The socket flow path 123Ba forms a passage along an inclined surface 123Bb on the inner wall of the connection conduit 123B. A restriction element 124 bb is formed to connect with the lower end of the inclined surface 123Bb. The restriction element 124 bb defines a restricted flow path 124Bc that is eccentric to the center axis of the restriction element 124 bb having a preset diameter. The restricted flow path 124Bc and the lower end plane of the inclined surface 123Bb define a retention surface 124Bd.

[0246] In this drain socket 120B, the cleansing water flown into the toilet joint member 121B flows along the inclined surface 123Bbof the connection conduit 123B, changes its flow direction to the horizontal direction at the retention surface 124Bd, and is flown out of the restricted flow path 124Bc. In the drain socket 120B, the flow direction of cleansing water is changed to the horizontal direction by the positional relationship between the inclined surface 123Bb of the connection conduit 123B and the restricted flow path 124Bc of the restriction element 124 bb. This arrangement ensures generation of a water film in the vicinity of the restriction element 124 bb and thus instantly induces the siphon action.

[0247]FIG. 24 is a sectional view illustrating still another drain socket 120C in a fourth embodiment. The differences from the drain socket 120B shown in FIG. 23 are that a restriction element 124Cb is provided on the lower end of an outflow cylindrical member 125C, that is, in the vicinity of the flow outlet 124 a and that a restricted flow path 124Cc defined by the restriction element 124Cb is eccentric to an inclined surface 123Cb.

[0248] The flow path between the lower end of an inclined surface 123Cb and the restriction element 124Db is relatively longer to have a height H. The restricted flow path 124Cc defined by the restriction element 124Cb is formed in an eccentric layout, so that the cleansing water flowing along the inclined surface 123Cb hits against a retention surface 124Cd provided opposite to the inclined surface 123Cb. In the structure of this drain socket 120C, the cleansing water flowing along the inclined surface 123Cb. of a drain conduit joint member 124C hits against the retention surface 124Cd of the restriction element 124Cb to stay in the space between the lower end of the inclined surface 123Cb. and the restriction element 124Cb, so as to induce the siphon action. The eccentric layout of the restriction element 124Cb ensures instant induction of the siphon action of the cleansing water flowing along the inclined surface 123Cb. The cleansing water is kept in the long flow path (height H) between the inclined surface 123Cb. and the restriction element 124Cb. This increases the difference in water level from the cleansing water reserved in the bowl of the toilet body, thus enhancing the siphon action.

[0249]FIG. 25 is a sectional view illustrating another drain socket 120D in a fifth embodiment. The drain socket 120D shown in FIG. 25 has an outflow cylindrical member 125D extended to be lower than a socket fixation leg 128Dd, and a restriction element 124Db is provided on the lower end of the outflow cylindrical member 125D. The illustration of FIG. 25 regards the case of installing a toilet in a lavatory on a second floor in a multi-story building. The drain socket 120D is fixed to the floor surface FL by means of the socket fixation leg 128Dd. The outflow cylindrical member 125D of the drain socket 120D is extended downward from the floor surface FL of the second floor and is inserted into a drain conduit P laid in a space between the ceiling of the first floor and the floor surface FL of the second floor. The drain conduit P is connected to a traverse drain conduit PS bent substantially at right angles.

[0250] The restriction element 124Db is attached to the lower end of the drain socket 120D. FIG. 26 is an enlarged sectional view illustrating the vicinity of the restriction element 124Db. The restriction element 124Db is detachably attached to the lower end of the outflow cylindrical member 125D. The restriction element 124Db has a restriction plate 124Dd that defines a restricted flow path 124Dc. A female screw 124De is formed on the outer circumference of the restriction plate 124Dd. The female screw 124De engages with a male screw 125Da formed on the lower end of the inner circumference of the outflow cylindrical member 125D. The restriction plate 124Dd is thus detachably attached to the lower end of the outflow cylindrical member 125D. An attachment tab 124Df is formed on the lower end of the outer circumference of the restriction plate 124Dd to facilitate the attachment work.

[0251] In the drain socket 120D of this embodiment, the outflow cylindrical member 125D is extended below the floor surface FL, and the restriction element 124Db is provided on the lower end of the outflow cylindrical member 125D. This increases the difference in water level and thereby enhances the siphon action. The restriction element 124Db is formed separately from the drain socket 120D. This facilitates manufacture of the drain socket 120D. The restriction element 124Db is securely attached to the outflow cylindrical member 125D by means of the male screw 125Da and the female screw 124De. This arrangement thus effectively prevents detachment or shift of the restriction element 124Db, which undesirably affects induction of the siphon action.

[0252] The restriction element may have another construction for attachment; for example, the structure of a restriction element 124Ea shown in FIG. 27 and the plan view of FIG. 28 is applicable. Engagement projections 124Ec are formed on both sides of a restriction plate 124Eb of the restriction element 124Ea. The engagement projections 124Ec are inserted into recesses 125Ea formed on the lower end of an outflow cylindrical member 125E, and are pressed by engagement arms 125Eb pivotably supported on the lower end of the outflow cylindrical member 125E. In this construction, the restriction element 124Ea is positioned in the circumferential direction by the positional relationship between the engagement projections 124Ec and the mating recesses 125Ea. Even when the restricted flow path has an eccentric layout, this arrangement ensures the secure attachment of the restriction element at a predetermined position and thereby inductions of the desired siphon action.

[0253]FIG. 29 is a sectional view illustrating the vicinity of another drain socket 120F in a sixth embodiment. FIG. 30 shows the positional relationship between a trap drain conduit 111Fb of a toilet body 111F and the drain socket 120F. This embodiment is characterized by the structure of a restriction element 116Fa provided on a drainage port 116F of the toilet body 111F and the structure of a toilet joint member 121F of the drain socket 120F positioned by the trap drain conduit 111Fb. The restriction element 116Fa provided in the vicinity of the drainage port 116F causes the flow of cleansing water to be retained in the upstream of the drain socket 120F and advances the induction timing of the siphon action. This leads to a decrease in required flow rate of cleansing water.

[0254] A positioning notch 111Fc is formed on the lower end of the trap drain conduit 111Fb. A positioning projection 121Fa of a toilet joint member 121F of the drain socket 120F mates with the positioning notch 111Fc. The positioning engagement enables the drain socket 120F to be fixed to the toilet body 111F without deviating the position of the restriction element 116Fa.

[0255] The restriction element 116Fa may be formed integrally with or separately from the trap drain conduit 111Fb. The restriction element 116Fa may have another structure, for example, a step-like structure or an eccentric layout.

[0256] There are some modifications of the second through the sixth embodiments.

[0257] (1) An attachment mark may be provided at any easily visible position, for example, on the outer wall of the drain socket, as a marker for clearly showing the front or back of the drain socket in the process of attachment of the drain socket. The attachment mark assures accurate attachment of the drain socket and thereby enables the restriction element to be attached to the toilet body at the right position.

[0258] (2) The outflow cylindrical member 125, the first cylindrical joint element 126, and the second cylindrical joint element 127 of the toilet joint member 121 are not restricted to be concentric, but may have an eccentric layout to instantly induce the siphon action as long as it assures the smooth discharge of excrement.

[0259] (3) The above embodiments regard the drain conduits P of polyvinyl chloride. The technique of the present invention is, however, also applicable to a lead drain conduit via an adaptor.

[0260] (4) The outer wall of the outflow cylindrical member 125 of the drain socket 120 and the inner wall of the first cylindrical joint element 126, as well as the outer wall of the first cylindrical joint element 126 and the inner wall of the second cylindrical joint element 127 may have a slope with an increasing diameter toward the downstream. Such arrangement facilitates the joint work with the drain conduit P and removal from the die in the process of injection molding the drain socket 120.

[0261] (5) Notches may be formed in the outflow cylindrical member 125 and the first cylindrical joint element 126, in order to facilitate application of the adhesive on the connection surfaces of the first cylindrical joint element 126 and the second cylindrical joint element 127. In this modified structure, the outflow cylindrical member 125 and the first cylindrical joint element 126 may have an identical length of downward extension according to the requirements.

[0262] Seventh and eighth embodiments are discussed below.

[0263]FIG. 31 is a sectional view illustrating the vicinity of a toilet 210 with a drain socket 220 in a seventh embodiment of the present invention. The toilet 210 has a pottery toilet body 211 including a bowl 211 a integrated with a drain conduit 211 b, a resin drain socket 220, a cleansing water retention module 230 attached to the drain socket 220, and a water tank. The drain socket 220 connects a drainage port 216 of the toilet body 211 to a drain conduit P protruded from the floor surface FL.

[0264] The procedure discussed in the second embodiment with reference to FIGS. 12 and 13 is applicable for connection with the drain conduit P. The drain socket 220 may be disposed at different distances L1 (120 mm) and L2 (200 mm) from the front wall WF of the lavatory, and is applicable to the four different specifications of the drain conduit P and the two different layouts. The drain socket 220 and the cleansing water retention module 230 are discussed in detail.

[0265]FIG. 32 is an enlarged sectional view illustrating the drain socket 220 and the cleansing water retention module 230 shown in FIG. 31. FIG. 33 is a sectional view illustrating the vicinity of the drain socket 220 taken in a direction perpendicular to the longitudinal axis of the toilet body 211. As shown in FIGS. 32 and 33, the drain socket 220 includes a toilet joint member 221, a connection conduit 223, a drain conduit joint member 224, a socket fixation member 228 (see FIG. 35), and toilet fixation members 229 (see FIG. 33), which are integrally made of a resin. The cleansing water retention module 230 for inducing the siphon action is attached to the upper portion of the drain socket 220.

[0266] The toilet joint member 221 receives the outlet side of the drain conduit 211 b inserted therein, so as to connect the drainage port 216 of the drain conduit 211 b to a flow inlet 221 a.

[0267] The connection conduit 223 defines an inclined connection flow path 223 a, which connects the flow inlet 221 a with a flow outlet 224 a in an eccentric manner. An eccentric distance La of the connection conduit 223 is set to satisfy the relation of La=(L2−L1)/2.

[0268] The drain conduit joint member 224 has an outflow cylindrical member 225 with the flow outlet 224 a, as well as a first cylindrical joint element 226 and a second cylindrical joint element 227, which are concentric with the flow outlet 224 a. The outflow cylindrical member 225 is inserted into the drain conduit P led to the sewer, so as to prevent leakage of cleansing water.

[0269]FIG. 34 is an enlarged sectional view illustrating the vicinity of the drain conduit joint member 224. Referring to FIG. 34, the first cylindrical joint element 226 and the second cylindrical joint element 227 are cylindrical bodies used to alternatively connect with the drain conduits P of the different outer diameters D1 and D2 (see FIG. 12). A gap d1 between the outflow cylindrical member 225 and the first cylindrical joint element 226 and a gap d2 between the first cylindrical joint element 226 and the second cylindrical joint element 227 are designed to be greater than the wall thickness t2 of the drain conduit P. These gaps d1 and d2 can thus receive all the drain conduits P inserted therein. The inner wall surface of the first cylindrical joint element 226 or the second cylindrical joint element 227 is bonded to the outer circumferential face of the drain conduit P fitted therein via an adhesive.

[0270] The specific structure discussed below facilitates the bonding work. The first cylindrical joint element 226 is formed to be protruded downward from the outflow cylindrical member 225, whereas the second cylindrical joint element 227 is formed to be protruded downward from the first cylindrical joint element 226. Namely the inner cylinder is shorter than the outer cylinder. This arrangement assures smooth application of the adhesive on the inner wall surface of the first cylindrical joint element 226 or the inner wall surface of the second cylindrical joint element 227, thereby facilitating the bonding work.

[0271]FIG. 35 is a side view of the drain socket 220. FIG. 36 is a bottom view of the drain socket 220. As shown in FIGS. 35 and 36, the socket fixation member 228 is formed integrally with the bottom of the drain socket 220. The socket fixation member 228 is a site functioning to fix the drain socket 220 to the floor surface FL. The socket fixation member 228 includes a quasi-quadrangular flat plate 228 a extending from the outer circumference of the second cylindrical joint element 227 in the horizontal direction. The drain socket 220 is fixed to the floor surface FL by means of screws 228 c via four tapped holes 228 b formed in the flat plate 228 a.

[0272] Referring back to FIG. 33, the toilet fixation members 229, 229 are formed on the side of the drain socket 220. The toilet fixation members 229, 229 are a site functioning to fix the toilet body 211 above the drain socket 220. The toilet fixation members 229, 229 have screw fixation elements 229 a, 229 a on the respective upper faces thereof. The screw fixation elements 229 a, 229 a are formed to be symmetrical both about the longitudinal axis of the toilet body 211 and about the axis perpendicular to the longitudinal axis. Even in the case where the orientation of the drain socket 220 is front side back, the screw fixation elements 229 a, 229 a are placed to face lower end fixation elements 211 d of the toilet body 211.

[0273]FIG. 40 is an enlarged sectional view illustrating the vicinity of the cleansing water retention module 230 attached to the upper portion of the drain socket 220. FIG. 41 is a top view illustrating the cleansing water retention module 230. With referring to FIGS. 40 and 41, the cleansing water retention module 230 includes a retention body 231 and a rubber attachment 232. The retention body 231 has a cylindrical side wall 231 a that is fitted in the toilet joint member 221 on the upper portion of the drain socket 220, a lower restriction 231 b that is extended toward the inner circumference from the lower end of the side wall 231 a, and defines a flow path 231 c, and a support recess 231 d that supports the rubber attachment 232. These constituents of the retention body 231 are integrally made of a resin. The rubber attachment 232 has a ring-shaped fixation projection 232 a, which is pressed into the support recess 231 d and is accordingly attached to the retention body 231, a sealing member 232 b that seals the outer circumference of the drainage port 216 of the drain conduit 211 b, a large number of folds 232 c that are formed along the inner circumference of the sealing member 232 b to support the periphery of the drain conduit 211 b, and an upper restriction 232 d. These constituents of the rubber attachment 232 are integrally made of a rubber. The retention body 231 of the cleansing water retention module 230 is attached to the upper portion of the drain socket 220, while the sealing member 232 b of the rubber attachment 232 seals the outer circumference of the drain conduit 211 b of the toilet body. The cleansing water retention module 230 has the two restrictions along the stream of cleansing water, that is, the upper restriction 232 d and the lower restriction 231 b. These two restrictions narrow the flow path area to temporarily retain the cleansing water discharged from the drainage port of the drain conduit 211 b and induce the siphon action.

[0274] The following describes the installation process of the toilet 210. In a first example, the toilet body 211 is installed with the drain socket 220 when the drain conduit PA shown in FIG. 12(A) is disposed at the distance L1 (120 mm) shown in FIG. 13(A).

[0275]FIG. 37 shows a process of setting the drain socket 220. The drain conduit P is cut at a height of 60 mm from the floor level. The procedure then checks the front-back orientation of the drain socket 220, adjusts the centerline of the drain socket 220 with the imaginary installation centerline of the toilet body 211, inserts the first cylindrical joint element 226 of the drain socket 220 into the drain conduit P, and tentatively positions the drain socket 220 as shown in FIG. 38. The drain socket 220 is tentatively laid to make the toilet joint member 221 face front. The procedure then draws lines for positioning along the lower side of the drain socket 220 and utilizes the tapped holes 228 b of the socket fixation member 228 (see FIGS. 35 and 36) to form prepared holes in the floor surface FL.

[0276] The procedure detaches the drain socket 220 from the floor surface FL and applies an adhesive on the inner wall of the first cylindrical joint element 226 of the drain socket 220 and the outer circumferential face of the drain conduit P. The first cylindrical joint element 226 is then returned to the tentatively positioned place and fitted in the drain conduit P. The first cylindrical joint element 226 is accordingly bonded to the drain conduit P via the adhesive as shown in FIG. 32. The drain socket 220 is fixed to the floor surface FL by means of the screws in the four tapped holes 228 b formed in the socket fixation member 228.

[0277] The procedure subsequently positions the drainage port 216 of the toilet body 211 at the flow inlet 221 a of the toilet joint member 221 of the drain socket 220 as shown in FIG. 33, and lays the toilet body 211 on the floor surface FL. This causes the drainage port 216 to be inserted through the flow inlet 221 a of the toilet joint member 221 and sealed with the sealing member 232 b of the rubber attachment 232. Insertion of screws 229 b, 229 b through the lower end fixation elements 211 d of the toilet body 211 and the toilet fixation members 229, 229 fixes the toilet body 211 to the drain socket 220. The toilet body 211 is then fixed to the floor surface FL via non-illustrated fixation members.

[0278] In a second example, the drain socket 220 is connected when the drain conduit PA is disposed at the distance L2 (200 mm) from the front wall WF of the lavatory as shown in FIG. 13(B). This process is identical with the process of the first example, except that the orientation of the drain socket 220 is front side back. The procedure of the second example disposes the drain socket 220 to make the toilet joint member 221 face the front wall WF as shown in FIG. 39. When the drain conduit P is disposed at the different positions, the toilet body 211 is installed at the identical position by simply changing the orientation of the drain socket 220.

[0279] When the drain conduit P is disposed at the different positions, the structure of this embodiment enables the toilet body 211 to be installed at the identical position in the lavatory by simply changing the orientation of the drain socket 220. It is accordingly not necessary to provide different drain sockets 220 corresponding to the layout positions of the drain conduit P.

[0280] In a third example, the toilet body 211 is installed to the drain conduit P of a different outer diameter. The process with regard to the drain conduit PC or the drain conduit PD of the outer diameter D2 shown in FIG. 12(C) or 12(D) is identical with either of the above processes, except that the adhesive is applied on the inner circumferential face of the second cylindrical joint element 227 of the drain socket 220 shown in FIG. 32. The same drain socket 220 is applicable with a change of the adhesive application face corresponding to the outer diameter of the drain conduits PC and PD. The gap d1 between the outflow cylindrical member 225 and the first cylindrical joint element 226 and the gap d2 between the first cylindrical joint element 226 and the second cylindrical joint element 227 are greater than the wall thickness t2 of the drain conduits PB and PD as shown in FIG. 34. The same drain socket 220 is thus connectable with the thicker drain conduit P having the wall thickness t2.

[0281] The same drain socket 220 is applicable to the diverse drain conduits P having the different outer diameters, wall thicknesses, and layout positions as shown in FIGS. 12 and 13 under the same installation conditions by adequately selecting the orientation and the adhesive application face. The drain socket 220 accordingly has the excellent workability.

[0282] The drain socket 220 has the cleansing water retention module 230 as shown in FIG. 40 to ensure instant induction of the siphon action.

[0283] A supply of cleansing water fed from a non-illustrated cleansing water supply unit to the bowl 211 a of the toilet body 211 is flown into the drain socket 220 via the drain conduit 211 b. The cleansing water retention module 230 has the upper restriction 232 d in the vicinity of the flow inlet 221 a and the lower restriction 231 b along the stream of cleansing water. The local change of the flow path area in two stages enhances the effect of delaying the flow of cleansing water in the connection flow path 223 a, thus readily inducing the siphon action. The arrangement of the two-stage restrictions, the upper restriction 232 d and the lower restriction 231 b, allows a greater flow path area per restriction, compared with the arrangement of the single restriction. This arrangement thus ensures the smooth and quick discharge of sanitary sewage including excrement.

[0284] The cleansing water retention module 230 is formed separately from the drain socket 220. The lower restriction 231 b and the upper restriction 232 d of complicated shapes can thus be formed by taking into account the optimum design conditions for induction of the siphon action, without any restriction of the manufacturing conditions, for example, removal from the die, in the process of injection molding the drain socket 220.

[0285] The drain socket 220 has the connection conduit 223 that defines the inclined connection flow path 223 a to make the flow outlet 224 a eccentric to the flow inlet 221 a. This gives the effect of delaying the flow of cleansing water in the upstream of the connection flow path 223 a, thus readily inducing the siphon action.

[0286] The connection flow path 223 a is not required to have a large draft of the die in the process of injection molding, that is, to have an unnecessarily large flow path area. This arrangement enables a less flow rate of cleansing water to instantly induce the sufficient siphon action. The following describes a drain socket in another embodiment. FIG. 42 is a sectional view illustrating a drain socket 220B and a cleansing water retention module 230B in an eighth embodiment. As shown in FIG. 42, the drain socket 220B is characterized by a straight pipe structure having concentric flow inlet 221Ba and flow outlet 224Ba and by the cleansing water retention module 230B fitted in and bonded to an outflow cylindrical member 225B.

[0287] The cleansing water retention module 230B has a cylindrical side wall 231Ba and a restriction element 231Bb projected from the side wall 231Ba toward the inner circumference. The outer circumferential face of the side wall 231Ba is bonded to the inner circumference of the outflow cylindrical member 225B. The restriction element 231Bb is provided separately from the drain socket 220B, and is accordingly tapered to have a narrower flow path area toward the downstream as the optimum condition for inducing the siphon action, without being limited by the contour of the drain socket 220B.

[0288]FIGS. 43 through 45 are sectional views illustrating modified examples of the cleansing water retention module 230B of FIG. 42. A cleansing water retention module 230C shown in FIG. 43 has a restriction element 231Cb disposed on the upper stream side relative to the cleansing water retention module 230B of FIG. 42. A cleansing water retention module 230D shown in FIG. 44 has a restriction element 231Db disposed on the lower stream side. A cleansing water retention module 230E shown in FIG. 45 has a restriction element 231Eb on the lowest-most stream side and a flow path 231Ec having a temporarily increasing flow path area from the upstream side to the downstream side. The flow path 231Ec of such construction enhances the effect of temporarily retaining the flow of cleansing water on the upstream side of the restriction element 231Eb, thus allowing instant induction of the siphon action.

[0289]FIGS. 46 through 52 are sectional views illustrating cleansing water retention modules of other structures. These cleansing water retention modules are characterized by the construction that a resin plate with a restriction element is fixed to the lower end of the outflow cylindrical member. A cleansing water retention module 230F shown in FIG. 46 has a ring-shaped engagement member 230Fa, which is disposed on the outer circumference thereof and receives the outer circumference of the lower end of the outflow cylindrical member 225B fitted therein.

[0290] A cleansing water retention module 230G shown in FIG. 47 is a resin plate, which is bonded to a flange 225Ga formed on the lower end of an outflow cylindrical member 225G.

[0291] A cleansing water retention module 230H shown in FIG. 48 has a positioning step 231Ha formed on the upper face of the outer circumference thereof. The step 231Ha engages with a positioning step 225Ha formed on the outer circumference of the lower end of an outflow cylindrical member 225H, so as to attain positioning.

[0292] A cleansing water retention module 230J shown in FIG. 49 has a positioning projection 231Ja formed on the upper face of the outer circumference thereof. The positioning projection 231Ja is fitted in an engagement aperture 225Jb formed in a flange 225Ja of an outflow cylindrical member 225J, so as to attain positioning.

[0293] A cleansing water retention module 230K shown in FIG. 50 has a plurality of engagement apertures 231Ka formed in the outer circumferential part thereof. Elastic projections 225Ka formed on an outflow cylindrical member 225K are pressed into the engagement apertures 231ka.

[0294] A cleansing water retention module 230L shown in FIG. 51 has a flange 231La formed on the outer circumference thereof. The flange 231La is joined with and fixed to a flange 225La formed on an outflow cylindrical member 225L via screws 231L.

[0295] A cleansing water retention module 230M shown in FIG. 52 is bonded and fixed to the lower end of an outflow cylindrical member 225M, which has a skirt element 225Ma of an increasing flow path area toward the downstream.

[0296] The seventh and the eighth embodiments discussed above may be changed or modified in diverse ways as mentioned below.

[0297] The structure of the drain socket is not specifically restricted. For example, the drain socket may have eccentric flow inlet and flow outlet or a straight pipe structure. The drain socket may also be a wall drain type disposed on a front wall.

[0298] The following describes ninth through eleventh embodiments.

[0299]FIG. 53 is a vertical sectional view illustrating a siphon jet action-type toilet 310 with a drain socket 360 connected thereto in a ninth embodiment of the present invention. The siphon jet action-type toilet 310 makes cleansing water ejected from a jet nozzle 322 discussed later to induce the siphon action. Respective constituents of the toilet 310 are discussed below with reference to FIG. 53.

[0300] Referring to FIG. 53, the toilet 310 has a bowl 320 to receive sanitary sewage including excrement and toilet paper therein. A peripheral wall of the bowl 320 has a water-submerged surface 323 that is in contact with reserved water RW even in a non-cleansing time of the toilet 310 and an exposed surface 324 that is not in contact with the reserved water RW in the non-cleansing time of the toilet 310.

[0301] The toilet 310 is provided with a mechanism for supplying water to the bowl 320 (hereinafter referred to as the supply mechanism) and a mechanism for discharging excrement in the bowl 320 toward a drain conduit 390 (hereinafter referred to as the drainage mechanism).

[0302] The supply mechanism is discussed first. A cleansing water supply aperture 340, which is a hole connecting with a water supply pipe SL of a water tank WT, is provided behind the toilet 310. A cleansing water supply conduit 341, which defines a flow path of cleansing water led from the water tank WT, is disposed inside the toilet 310 along a passage from the cleansing water supply aperture 340 towards the bowl 320. A branch hole 342 is formed on the upper side of the inner wall of the cleansing water supply conduit 341.

[0303] A specific part of the cleansing water supply conduit 341 downstream the branch hole 342 forms a retention space 341 a extended to have an inclined down slope. A jet supply nozzle 345 is formed in the side wall of the retention space 341 a and is connected to the jet nozzle 322, which faces a drainage port 325, via a jet supply conduit 346 curved inside the toilet.

[0304] The cleansing water supply conduit 341 communicates with rim supply conduits 343 via the branch hole 342. The rim supply conduits 343 are hollow spaces formed behind a rim member 321 and along the inner circumference on the upper end of the bowl 320. A large number of water outlets 344 are formed in a bottom wall of the rim supply conduits 343 at preset intervals.

[0305] A supply of cleansing water fed from the high water level in the water tank WT to the cleansing water supply aperture 340 by free wall is guided by the inclined down slope of the cleansing water supply conduit 341 and is flown into the retention space 341 a. The cleansing water reaching the retention space 341 a then enters the jet supply nozzle 345, which is a hole formed in the side wall of the retention space 341 a. The supply of cleansing water is then fed to the jet supply conduit 346 and ejected from the jet nozzle 322. The jet nozzle 322 is located to substantially face the drainage port 325 across a recess 326 as shown in FIG. 53. Energy of cleansing water is thus transmitted to the drainage mechanism of and after the drainage port 325 without any significant waste.

[0306] Water kept in the water tank WT is pressed by free fall and is fed as a supply of cleansing water at once to the cleansing water supply conduit 341. The retention space 341 a, the lower oblique division of the cleansing water supply conduit 341, is filled with water after start of each flushing action. Part of the cleansing water is supplied from the branch hole 342 to the rim supply conduits 343. The flow of cleansing water supplied to the rim supply conduits 343 is ejected from the water outlets 344 formed in a rear face of the rim member 321.

[0307] The drainage mechanism has the construction discussed below. As shown in FIG. 53, a drain conduit 330 is formed as a flow path of water and excrement and is disposed after the drainage port 325, which is formed behind the recess 326 working as the excrement reservoir. The drain conduit 330 has a connection pathway 331 that is extended from the drainage port 325 in an oblique upward direction, an ascending pathway 332 that communicates with the connection pathway 331 and is extended in the oblique upward direction, and a descending pathway 333 that communicates with the ascending pathway 332 and is extended in a downward direction. The height between a floor surface FL, on which the toilet 310 is installed and the lower end of the descending pathway 333 is set to be approximately 120 mm.

[0308] The descending pathway 333 goes over a weir 334, which is the highest point of the lower inner wall of the ascending pathway 332, and is extended downward in a practically vertical direction toward the drain conduit 390 as shown in FIG. 53. The drain conduit 330 in a neighborhood of the weir 334 accordingly has a curved shape. This part of the curved shape is hereinafter referred to as a curved section 335.

[0309] These flow paths are formed integrally with the toilet 310 made of pottery by utilizing a plaster or resin mold, although the flow paths may be made of a different material separately from the toilet 310. For example, all or part of the flow paths may be made of another material like resin and connected to the drainage port 325.

[0310] The cleansing water is vigorously jetted from the jet nozzle 322 toward the drainage port 325. This jet action causes the reserved water RW in the connection pathway 331 and the ascending pathway 332 and the excrement in the recess 326 to be pressed up toward the weir 334. The water level in the ascending pathway 332 thus abruptly rises and exceeds the standard height of water level WL to make the connection pathway 331, the ascending pathway 332, and the curved section 335 filled with water. There is accordingly a water level difference between the full water level in the curved section 335 and the surface of the reserved water RW in the bowl 320. The water level difference causes a pressure difference between the descending pathway 333 and the bowl 320 and produces a downward pulling force. This series of phenomena is called the siphon action. The siphon action causes the excrement in the bowl 320 to be drawn toward the weir 334, together with the dirt reserved water RW and the cleansing water.

[0311] The descending pathway 333 includes an expanded section 333 a having a greater pipeline diameter and a tapered end 333 b having a narrower opening area than that of the expanded section 333 a. The restriction structure, which defined by the expanded section 333 a and the tapered end 333 b, functions to temporarily retain the flow of cleansing water passing through the descending pathway 333 and extend the duration of the siphon action.

[0312] The descending pathway 333 is connected to the drain conduit 390, which is composed of polyvinyl chloride and rises from the floor surface FL, via a resin drain socket 360. The drain conduit 390 corresponds to the ‘sewer’ in claims.

[0313] The distance from the rear end of the toilet 310 illustrated in FIG. 53 to the center of the drain conduit 390 is 180 mm, and the distance from the rear end of the water tank WT attached to the toilet 310 to the center of the drain conduit 390 is 190 mm. Namely arrangement of the drain conduit 390 rising upward to a position of about 200 mm apart from the wall of the lavatory enables the assembly of the toilet 310 and the water tank WT to be installed with a clearance of 10 mm between the rear face of the water tank WT and the wall of the lavatory. Installation of the assembly of the toilet 310 and the water tank WT under such conditions allows the layout of the drain conduit 390 at a position close to the construction wall. This layout shortens the distance from the drain conduit 390 to a pipe space and ensures smooth transport of excrement. The distance may be 200 mm or less when no consideration is given to the clearance from the wall of the lavatory.

[0314] The detailed structure of the drain socket 360 is illustrated in FIG. 54. The drain socket 360 mainly has two members, a base member 380 that is fixed to the floor surface FL with bolts 385 and a main body member 371 that is connected to the base member 380 and defines a main conduit 373 as the flow path of the reserved water RW, cleansing water, and excrement. The base member 380 and the main body member 371 respectively correspond to the first member and the second member in the claims. The details of the respective members are discussed below.

[0315] As shown in FIG. 54, the main body member 371 has a descending pathway fitting element 371 a on the upper end thereof, which receives the lower end of the descending pathway 333 therein. The lower end of the descending pathway 333 is placed on a setting plane 371 b of the descending pathway fitting element 371 a. The drain socket 360 is connected to the descending pathway 333 on this setting plane 371 b.

[0316] The hollow and cylindrical main conduit 373 is formed below the descending pathway fitting element 371 a. The main conduit 373 defines the flow path of the reserved water, cleansing water, and excrement flown through the descending passage 333. The flow path sectional area of the main conduit 373 abruptly decreases in the vicinity of the inlet of the main conduit 373 and then gradually decreases toward the outlet of the main conduit 373. Namely the main conduit 373 has the large and small restrictions.

[0317] Two recesses, a first ring-shaped recess 364 and a second ring-shaped recess 362, are formed around the outer circumference of the main conduit 373. Here the first ring-shaped recess 364 is closer to the main conduit 373 than the second ring-shaped recess 362. Both the first ring-shaped recess 364 and the second ring-shaped recess 362 are grooves concentric with the outer circumference of the main conduit 373. Formation of the first ring-shaped recess 364 and the second ring-shaped recess 362 defines a first ring-shaped projection 374 protruded downward in a cylindrical shape therebetween.

[0318] As shown in FIG. 54, the drain conduit 390 is inserted into the second ring-shaped recess 362. The drain conduit 390 is clamped by the resilient force of ribs 366 provided on the inner circumferential wall and the outer circumferential wall on the upper side of the second ring-shaped recess 362.

[0319] The ribs 366 are provided by bonding a rubber material having a little elasticity and a preset thickness to the inner circumferential wall and the outer circumferential wall. The ribs 366 on the inner circumferential wall are positioned to face the ribs 366 on the outer circumferential wall. There is an interval of approximately 1.5 mm between the ribs 366 on the inner circumferential wall and the ribs 366 on the outer circumferential wall. The drain conduit 390 is interposed between the ribs 366 on the inner circumferential wall and the ribs 366 on the outer circumferential wall and softly clamped by the ribs 366. The drain conduit 390 is connected to the main body member 371 via such clamping.

[0320] As shown in FIG. 54, a second ring-shaped projection 368 protruded downward in a cylindrical shape is formed outside the second ring-shaped recess 362. The second ring-shaped projection 368 has engagement pieces 389 protruded in the outer circumferential direction. The drain socket 360 is assembled by fitting the second ring-shaped projection 368 with the engagement pieces 389 in the base member 380. The engagement pieces 389 are formed at four positions on the end of the second ring-shaped projection 368. The arrangement will be discussed later with the method of fitting the second ring-shaped projection 368 into the base member 380.

[0321] In the assembled drain socket 360, a cover member 387, which is the lower circumferential wall of the main body member 371, covers over the base member 380. A window 388 discussed later (not shown in FIG. 54) is formed in part of the cover member 387.

[0322] The following describes the base member 380. The base member 380 is a donut-shaped member having a hollow center of a slightly greater diameter than the outer diameter of the drain conduit 390. A circumferential groove is formed in the base member 380 from its top face to a depth that is close to the bottom and is substantially equal to the dimension of the second ring-shaped projection 368. This circumferential groove forms a ring-shaped recess 384. The second ring-shaped projection 368 of the main body member 371 is inserted into this ring-shaped recess 384.

[0323] Engaging elements 382 are provided on the outer circumferential wall of the ring-shaped recess 384 to be mated with the engagement pieces 389 on the end of the second ring-shaped projection 368. The construction of the engaging elements 382 is discussed with reference to FIGS. 55 through 57. FIG. 55 shows the top face of the base member 380. As shown in FIG. 55, three standard engagement piece-engaging elements 382 a and one protruded engagement piece-engaging element 382 p are formed as the engaging elements 382 on the base member 380. The front side of the base member 380 is the right side in the drawing of FIG. 55. The protruded engagement piece-engaging element 382 p is positioned on the front side of the base member 380 (that is, on the right side in FIG. 54).

[0324] As shown by the two-dot chain line in FIG. 55, three standard engagement pieces 389 a having a shorter length and one protruded engagement piece 389 p having a longer length are formed on a specific end of the second ring-shaped projection 368 closer to the main body member 371. The standard engagement piece 389 a is mated with the standard engagement piece-engaging element 382 a on the base member 380, whereas the protruded engagement piece 389 p is mated with the protruded engagement piece-engaging element 382 p on the base member 380. As clearly seen in FIG. 55, the standard engagement pieces 389 a are protruded from the outer circumferential face of the base member 380 in the mated state.

[0325] Referring to FIG. 55, a vertical groove 382 b or 382 q extended straightly from a top face 380 a to the bottom of the base member 380 and horizontal grooves 382 c or 382 r extended in a horizontal direction from the vertical groove 382 b or 382 q are formed on the standard engagement piece-engaging element 382 a or the protruded engagement piece-engaging element 382 p. The vertical groove 382 q and the horizontal grooves 382 r are cut to a greater depth than that of the vertical groove 382 b and the horizontal grooves 382 c. The vertical groove 382 q penetrates through the outer circumferential wall of the base member 380.

[0326] The vertical groove 382 b and the horizontal grooves 382 c formed in the standard engagement piece-engaging element 382 a are shown in FIG. 56. FIG. 56 shows the cross section of the engaging element 382, taken on a centerline C-C in FIG. 54. As shown in FIG. 56, the standard engagement piece-engaging element 382 a has eight horizontal grooves 382 c along the vertical groove 382 b. The width of the vertical groove 382 b and the height of the horizontal grooves 382 c are set to allow insertion of the engagement piece 389 a. The horizontal groove 382 c has a slightly less height in the vicinity of a midd1e projection 381. The protruded engagement piece-engaging element 382 p also has eight horizontal grooves 382 r in the same layout.

[0327] The main body member 371 is covered over the base member 380 having the above construction, and the four engagement pieces 389 a and 389 p on the end of the second ring-shaped projection 368 are inserted into the vertical grooves 382 b and 382 q of the respective mating engaging elements 382 a and 382 p as shown in FIGS. 55 and 56. The main body member 371 is then rotated clockwise at a preset position, and the four engagement pieces 389 a and 389 p enter the horizontal grooves 382 c and 382 r of the respective mating engaging elements 382 a and 382 p. The rotation of the main body member 371 with a force of or over a predetermined level causes the four engagement pieces 389 a and 389 p entering the horizontal grooves 382 c and 382 r to ride over the projections 381 and to be mated with the corresponding engaging elements 382 a and 382 p. The main body member 371 is accordingly attached to the base member 380.

[0328] In the example of FIGS. 53 and 54, the four engagement pieces 389 a and 389 p on the end of the second ring-shaped projection 368 are fitted in the lower-most horizontal grooves 382 c and 382 r. This leads to the minimum height of the drain socket 360 from the floor surface FL.

[0329] The drain socket 360 has the construction discussed above. The method of attaching the drain socket 360 to the descending pathway 333 of the toilet 310 and the drain pie 390 is discussed below. The procedure first applies an adhesive on the rear face of the base member 380, places the drain conduit 390 through the hollow center of the base member 380, and bonds and fixes the base member 380 onto the floor surface FL with four bolts 385. The main body member 371 is covered over the base member 380 to make the second ring-shaped projection 368 inserted into the ring-shaped recess 384, so that the drain conduit 390 is fitted in the second ring-shaped recess 362 of the main body member 371.

[0330] The procedure then adjusts the height of the drain socket 360 from the floor surface FL to the distance between the floor surface FL and the lower end of the descending pathway 333. The method of adjustment is discussed below with reference to FIGS. 57 through 59. FIG. 57 is a perspective view illustrating the base member 380. As shown in FIG. 57, the vertical groove 382 q and the eight horizontal grooves 382 r are exposed to the outer circumferential face on the front side of the base member 380. Eight scale lines are engraved adjacent to the respective horizontal grooves 382 r at pitches of 10 mm along the height. Numerical values are engraved adjacent to the respective sale lines to represent the heights from the floor surface FL to the setting plane 371 b on which the descending pathway 333 is placed. More specifically, numerical values of 130 mm to 200 mm are shown by the unit of 10 mm as shown in FIG. 57.

[0331]FIG. 58 shows the front side of the drain socket 360, where the main body member 371 is covered over the base member 380 with the engraved numerical values and the four engagement pieces 389 a and 389 p are fitted in the lower-most horizontal grooves 382 c and 382 r. As shown in FIG. 58, in the state of attachment of the main body member 371 to the base member 380, the protruded engagement piece 389 p, the horizontal groove 382 r that receives the protruded engagement piece 389 p fitted therein, and the ‘scale line with the numerical value of 130 mm’ engraved adjacent to the horizontal groove 382 r are observable through the window 388, which is a horizontal slot formed by cutting part of the front side of the outer circumference of the main body member 371. When the four engagement pieces 389 a and 389 p are fitted in the lower-most horizontal grooves 382 c and 382 r, the height of the drain socket 360 from the floor surface FL to the setting plane 371 b is 130 mm. The protruded engagement piece 389 p arranged at the height corresponding to the ‘scale line with the numerical value of 130 mm’ is accordingly seen through the window 388.

[0332]FIG. 58 illustrate the drain socket 360 of FIG. 53 seen from the front face (that is, the face on the side of the free end of the toilet 310 when the drain socket 360 is attached to the toilet 310). In the toilet 310 shown in FIG. 53, the height from the floor surface FL, on which the toilet 310 is installed, to the lower end of the descending pathway 333 is approximately 130 mm. The drain socket 360 is thus arranged under the condition of the least height (the height of 130 mm) from the floor surface FL to the setting plane 371 b.

[0333] The height of the drain socket 360 from the floor surface FL is adjusted according to the following procedure. When the main body member 371 engaged via the horizontal grooves 382 c and 382 r is rotated counterclockwise with a force of or over a predetermined level, the four engagement pieces 389 a and 389 p ride over the projections 381 and move to the vertical grooves 382 b and 382 q. This releases the engagement of the four engagement pieces 389 a and 389 p and makes the main body member 371 movable in the vertical direction along the vertical grooves 382 b and 382 q. The drain conduit 390 is softly clamped by the ribs 366. The ribs 366 slide on the surface of the drain conduit 390 with a vertical movement of the main body member 371. This arrangement effectively prevents the drain conduit 390 from being moved in the vertical direction with the movement of the main body member 371.

[0334] The procedure then vertically moves the main body member 371 to a desired position. The movement to the desired position is checked by referring to the ‘scale line engraved with the corresponding numerical value’ discussed above. For example, when the height of the drain socket 360 from the floor surface FL is raised from 130 mm to 200 mm, the main body member 371 is elevated until the protruded engagement piece 389 p reaches the position of the ‘scale line with the numerical value of 200 mm’.

[0335] The window 388 is open with a little margin in the direction of setting the protruded engagement piece 389 p in the horizontal groove 382 r (leftward in the drawing of FIG. 58). In the example of FIG. 58, the window 388 is open to have a margin on the left side of the head letter ‘1’ of the numerical value representing the height of the drain socket 360 from the floor surface FL. Even when the position of the window 388 is shifted counterclockwise with the counterclockwise rotation of the main body member 371 to release the engagement for adjustment of the height, all the letters of the numerical value representing the height of the drain socket 360 are observable through the window 388, together with the protruded engagement piece 389 p located in the vertical groove 382 q. This arrangement allows the user to check the current position of the main body member 371 by referring to the numerical value in the process of adjustment of the height of the drain socket 360 from the floor surface FL.

[0336]FIG. 59 shows the drain socket 360 after adjustment of the height of the drain socket 360 from the floor surface FL to 200 mm. The protruded engagement piece 389 p and the window 388 are both provided on the main body member 371 and are shifted in the vertical direction with the vertical movement of the main body member 371. When the height of the drain socket 360 from the floor surface FL is adjusted to 200 mm, the protruded engagement piece 389 p moved upward with the window 388 is fitted in the upper-most horizontal groove 382 r. The protruded engagement piece 389 p arranged at the height corresponding to the ‘scale line with the numerical value of 200 mm’ is accordingly observable through the window 388 as shown in FIG. 59. The height of the drain socket 360 from the floor surface FL is expressed by the position of the protruded engagement piece 389 p on the front side of the drain socket 360.

[0337] After adjustment of the height of the drain socket 360 from the floor surface FL to the distance between the floor surface FL and the lower end of the descending pathway 333, a seal member for preventing water leakage is set on the descending pathway fitting element 371 a, and the lower end of the descending pathway 333 of the toilet 310 is inserted into the descending pathway fitting element 371 a. This completes the attachment of the drain socket 360 to the descending pathway 333 and the drain conduit 390.

[0338] Adjustment of the height of the drain socket 360 from the floor surface FL changes the overall length of the drain socket 360. The overall length of the drain socket 360 represents the distance between a site of the drain socket 360 closest to the descending pathway 333 and another site closest to the drain conduit 390. In the example of FIG. 54, the overall length of the drain socket 360 is a distance 11 between the top face of the descending pathway fitting element 371 a and the bottom of the base member 380 that is in contact with the floor surface FL.

[0339]FIG. 60 is a vertical sectional view illustrating the drain socket 360 adjusted to the height of 200 mm from the floor surface FL and attached to another toilet 510. Like the toilet 310 discussed above, the toilet 510 has a drain conduit including a connection pathway, an ascending pathway, and a descending pathway 533. Unlike the toilet 310, however, the distance between the floor surface FL and the lower end of the descending pathway 533 is approximately 200 mm.

[0340] In the state of FIG. 60, the four engagement pieces 389 a and 389 p on the end of the second ring-shaped projection 368 are fitted in the upper-most horizontal grooves 382 c and 382 r. This makes the main body member 371 attached to the base member 380. The main body member 371 clamps the drain conduit 390 via the ribs 366 provided on the deeper section of the second ring-shaped recess 362 and is thereby connected to the drain conduit 390. The lower end of the descending pathway 533 having the height of approximately 200 mm from the floor surface FL is placed on the setting plane 371 b of the descending pathway fitting element 371 a, so that the main body member 371 is connected to the descending pathway 533. Even when the height of the drain socket 360 is adjusted and the overall length of the drain socket 360 is changed, the descending pathway 533 is smoothly connectable to the drain conduit 390 via the drain socket 360.

[0341] The positional relation between the main body member 371 and the base member 380 in FIG. 60 is changed to be apart from each other, compared with the positional relation in FIG. 54. More specifically, the distance from the floor surface FL to the setting plane 371 b of the main body member 371 is changed to 130 mm to 200 mm. A distance 12 between the top face of the descending pathway fitting element 371 a and the bottom of the base member 380 is accordingly longer by 70 mm than the distance 11 shown in FIG. 54.

[0342] In the ninth embodiment discussed above, the drain socket 360 includes the multiple members, the main body member 371 and the base member 380 that are separable in the direction of extending the main conduit 373. Various combinations of these members form diverse flow paths of the reserved water RW and cleansing water. The overall length of the drain socket 360 is freely variable. The common drain socket 360 is thus applicable to a plurality of different connections of the toilet 310 with the drain conduit 390.

[0343] In the arrangement of the ninth embodiment, the overall length of the drain socket 360 is changed by varying the height of the drain socket 360 from the floor surface FL. The same drain socket 360 is thus applicable to toilets having different heights from the floor surface FL to the lower end of the descending pathway 333. This enhances the applicability.

[0344] In the drain socket 360 of the ninth embodiment, the height of the drain socket 360 from the floor surface FL to the setting plane 371 b after adjustment is observably shown on the side face of the main body member 370. The arrangement enables the user to adjust the height of the drain socket 360 while checking the current position of the drain socket 360. This improves the workability in adjustment. Adjustment of the scale on the drain socket 360 to the designed dimension representing the height from the descending pathway of the toilet 310 to the floor surface FL attains the favorable connection. This application ensures the smooth adjustment without requiring measurement of the distance from the floor surface FL to the setting plane 371 b and the distance from the floor surface FL to the lower end of the descending pathway 333 and without requiring change of the length of the drain socket 360 in the process of positioning the drain socket 360 relative to the toilet 310 in the field.

[0345] In the ninth embodiment, the height of the drain socket 360 from the floor surface FL to the setting plane 317 b is expressed by the position of the protruded engagement piece 389 p. The height is thus readily shown without any special mechanism for display.

[0346] Clamping the drain conduit 390 via the ribs 366 discussed in the ninth embodiment is only one example of the technique of connecting the drain conduit 90 to the drain socket 360. Another technique may be applicable to connect the drain conduit 390 with the drain socket 360. For example, a resilient body other than rubber may be applied for the ribs 366. In another example, an identical material is applied to both the ribs 366 and the main body of the drain socket 360, and the ribs 366 are formed integrally with the second ring-shaped recess 362. In the structure that prevents water passing through the drain socket 360 from leaking outside the drain conduit 390, the drain conduit 390 may not be fitted in or bonded to the drain socket 360, but may be simply inserted in the second ring-shaped recess 362.

[0347] In the arrangement of the ninth embodiment, the drain conduit 390 is connected to the second ring-shaped recess 362 formed in the main body member 371 of the drain socket 360. In one possible modification, an equivalent structure to the second ring-shaped recess 362 is formed in the base member 380, and the drain conduit 390 is connected to the base member 380 of the drain socket 360.

[0348] The engagement construction of the four engagement pieces 389 a and 389 p on the main body member 371 with the corresponding engaging elements 382 a and 382 p of the base member 380 in the ninth embodiment is only one example of changing the positional relation between the main body member 371 and the base member 380. Another structure may be applied to change the positional relation between the main body member 371 and the base member 380. In one applicable structure, one aperture is formed in the main body member 371, and multiple apertures are formed in the base member 380 along the height thereof. The position of the aperture formed in the main body member 371 is adjusted to the position of a selected aperture formed in the base member 380, and a pin is inserted through these apertures.

[0349] In the ninth embodiment, the base member 380 is bonded and fixed to the floor surface FL with the bolts 385. Fixation of the base member 380 to the floor surface FL may, however, not always be required, but the base member 380 may just simply be placed on the floor surface FL. In the latter case, the height of the drain socket 360 may be adjusted as discussed above after the base member 380 is placed on the floor surface FL. Adjustment prior to the placement of the base member 380 on the floor surface FL, however, favorably enhances the working efficiency. The procedure pre-assembles the base member 380 with the main body member 371 and adjusts the height of the drain socket 360 to a desired level. The base member 380 assembled with the main body member 371 is then placed on the floor surface FL.

[0350] The following describes a tenth embodiment of the present invention. FIG. 61 is a vertical sectional view illustrating connection of a toilet 810 to a drain conduit 8390 via a drain socket 8360 in the tenth embodiment of the present invention. The toilet 810 and the drain socket 8360 shown in FIG. 61 have substantially common constituents to those of the toilet 310 and the drain socket 360 discussed above. In the drawing of FIG. 61, these common constituents are expressed by assignment of the numerals used in FIG. 54 to the lower three places of the respective symbols.

[0351] The drain socket 8360 has a base member 8380 and a main body member 8371 like the structure of the ninth embodiment. The structure thus allows adjustment of the height from the floor surface FL to a setting plane 8371 b of the main body member 8371.

[0352] The drain socket 8360 of the tenth embodiment has three primary members, that is, an inner drain conduit socket member 372 attached to the main body member 8371, in addition to the base member 8380 and the main body member 8371. The base member 8380 corresponds to the first member in the claims. The main body member 8371 corresponds to the first member or the first flow path defining member in the claims. The inner drain conduit socket member 372 corresponds to the second flow path defining member in the claims.

[0353] A hollow cylindrical main conduit 8373 is formed below a descending pathway fitting element 371 a. The main conduit 8373 defines the flow path of reserved water, cleansing water, and excrement flown through a descending pathway 833. Like the main conduit 373 of the ninth embodiment, the main conduit 8373 has two restrictions.

[0354] Referring to FIG. 61, the inner drain conduit socket member 372 is inserted into a first ring-shaped recess 8364 formed around the outer circumference of the main conduit 8373. The inner drain conduit socket member 372 is constructed by a combination of two members, a first cylindrical section 372 b of a quasi-cylindrical shape with a second cylindrical section 372 c of a cylindrical shape. More specifically, the inner drain conduit socket member 372 is provided by joining the upper end of the second cylindrical section 372 c with the lower end of the first cylindrical section 372 b.

[0355] The inner drain conduit socket member 372 is bonded to a desired position on the outer circumferential wall of the first ring-shaped recess 8364. Such bonding makes the inner drain conduit socket member 372 integrated with the main body member 8371. The bonding of the inner drain conduit socket member 372 causes the first cylindrical section 372 b to form an expanded conduit 375 having a greater pipeline diameter than that of the main conduit 8373 as the flow path communicating with the main conduit 8373. The second cylindrical section 372 c defines a straight line conduit 376 having practically the same diameter as that of the main conduit 8373 as the flow path communicating with the expanded conduit 375. The inner drain conduit socket member 372 accordingly extends the main conduit 8373, which is formed in the main body member 8371 as the flow path of the reserved water RW, cleansing water, and excrement, to the downstream side. As shown in FIG. 61, the inner drain conduit socket member 372 extends the flow path of the reserved water RW, cleansing water, and excrement to a specific position in the drain conduit 8390 below the floor surface FL.

[0356] The first cylindrical section 372 b includes a non-restricted element 372 p that has a substantially equal cross sectional area to the cross sectional area at the starting end of the first cylindrical section 372 b, and a first restriction 372 q that is arranged on the terminal end of the non-restricted element 372 p and has a decreasing cross sectional area toward the terminal end of the first cylindrical section 372 b. The terminal end of the first cylindrical section 372 b is protruded in the horizontal direction toward the center of the expanded conduit 375 and is then extended downward in the vertical direction. The cross sectional area of the first cylindrical section 372 b thus further decreases at the terminal end of the first cylindrical section 372 b. The terminal end of the first cylindrical section 372 b having such construction defines a second restriction 372 r.

[0357] The overall length of the drain socket 8360 having the above construction is varied by changing the position of attachment of the inner drain conduit socket member 372 to the main body member 8371. In the example of FIG. 61, the overall length of the drain socket 8360 is a distance 13 between the top face of a descending pathway fitting element 8371 a and the lower end of the second cylindrical section 372 c of the inner drain conduit socket member 372.

[0358]FIG. 62 shows the inner drain conduit socket member 372 attached to a different position of the main body member 8371. The first cylindrical section 372 b of the inner drain conduit socket member 372 in FIG. 62 is attached at a lower position on the outer circumferential wall of the first ring-shaped recess 8364, compared with the position in FIG. 61. A distance 14 between the top face of the descending pathway fitting element 8371 a and the lower end of the second cylindrical section 372 c of the inner drain conduit socket member 372 is accordingly longer than the distance 13 shown in FIG. 61.

[0359] Bonding of the inner drain conduit socket member 372 at the lower position enables the second cylindrical section 372 c of the inner drain conduit socket member 372 to be inserted into a deeper position in the drain conduit 8390. The first restriction 372 q and the second restriction 372 r are thus arranged at lower positions relative to the floor surface FL as the reference. This arrangement also lengthens the expanded conduit 375 and the straight line conduit 376 as the extended flow path of the main conduit 8373.

[0360] In the tenth embodiment described above, the drain socket 8360 includes the multiple members, the main body member 8371, the base member 8380, and the inner drain conduit socket member 372 that are separable in the direction of extending the main conduit 8373. Various combinations of these members form diverse flow paths of the reserved water RW and cleansing water. The overall length of the drain socket 8360 in the tenth embodiment is also freely variable. The common drain socket 8360 is thus applicable to a plurality of different connections of the toilet 810 with the drain conduit 8390.

[0361] In the structure of the tenth embodiment, the overall length of the drain socket 8360 is varied by changing the position of attachment of the inner drain conduit socket member 372 to the main body member 8371. This allows the length of the flow path formed in the drain socket 8360 to be changed to a desired value. In the tenth embodiment, the inner drain conduit socket member 372 is formed separately from the main body member 8371. The length of the flow path can be varied to a desired value by simply changing the position of attachment of the inner drain conduit socket member 372 to the first ring-shaped recess 8364. Namely the arrangement facilitates the variation in flow path length.

[0362] The inner drain conduit socket member 372 is constructed by the combination of the multiple sections, the first cylindrical section 372 b and the second cylindrical section 372 c. This arrangement facilitates the variation in flow path length. For example, a desired flow path length is set by simply selecting one among three optional patterns: both the first cylindrical section 372 b and the second cylindrical section 372 c are bonded to the first ring-shaped recess 8364; only the first cylindrical section 372 b is bonded to the first ring-shaped recess 8364; and neither the first cylindrical section 372 b nor the second cylindrical section 372 c is bonded to the first ring-shaped recess 8364.

[0363] The inner drain conduit socket member 372 has the two restrictions, that is, the first restriction 372 q and the second restriction 372 r. The positions of the restrictions are arbitrarily specified by taking into account the type of the toilet and the conditions of the drain conduit 8390.

[0364] For example, in the case of application of the drain socket 8360 to a siphon action-type toilet using a low flow rate of cleansing water, the inner drain conduit socket member 372 is set in the state shown in FIG. 62 (where the inner drain conduit socket member 372 is attached to the lower position in the first ring-shaped recess 364). This lowers the water retaining position in the expanded conduit 375 and increases the water head between the water retaining position and the vicinity of the weir. The greater water head enables the sucking force of reserved water and cleansing water produced by the siphon action to be utilized with a higher efficiency.

[0365] In the case where the drain conduit 8390 has only a little rise (that is, the depth from the upper end of the drain conduit 8390 to the inner bottom plane) from the laterally laid drain conduit 8390, for example, because of installation of the toilet 810 on the upper floor, only the first cylindrical section 372 b of the inner drain conduit socket member 372 is bonded to the first ring-shaped recess 8364. Alternatively the first cylindrical section 372 b is bonded to the upper portion of the first ring-shaped recess 8364. This arrangement lowers the water retaining position in the expanded conduit 375, while preventing the potential interference with the drain conduit 8390. The arrangement of the embodiment thus enhances the cleansing performance of the toilet, regard1ess of the rise of the drain conduit 8390.

[0366] In the case of application of the drain socket 8360 to a non-siphon action-type toilet, there is little necessity of retaining water in the drain socket 8360, so that the inner drain conduit socket member 372 is not required to be attached to the first ring-shaped recess 8364. The drain socket 8360 is thus commonly applicable to both the non-siphon action-type toilet and the siphon action-type toilet.

[0367] The construction of the tenth embodiment allows variations of both the height of the drain socket 8360 from the floor surface FL and the flow path length of the drain socket 8360. This arrangement ensures the cleansing performance of a substantially constant level, irrespective of the type of the toilet and the conditions of the sewer.

[0368] For example, application of the drain socket 8360 to two siphon action-type toilets having different heights from the floor surface FL to the lower end of the drain conduit gives the substantially equivalent cleansing power to the two siphon action-type toilets. The concrete procedure adjusts the height of the drain socket 8360 from the floor surface FL and attaches the inner drain conduit socket member 372 to the first ring-shaped recess 8364 in such a manner that the lower end of the inner drain conduit socket member 372 is placed at a substantially identical height. The flow rate of cleansing water and the water retaining position in the drain socket in one toilet are thus practically coincident with those in the other toilet. This arrangement thus ensures the equivalent cleansing power.

[0369] The following describes an eleventh embodiment of the present invention. FIG. 63 is a vertical sectional view illustrating connection of a toilet 1310 to a drain conduit 1390 via a drain socket 1360 in the eleventh embodiment of the present invention. The toilet 1310 and the drain socket 1360 shown in FIG. 63 have substantially common constituents to those of the toilet 310 and the drain socket 360 or 8360 discussed above. In the drawing of FIG. 63, these common constituents are expressed by assignment of the numerals used in FIGS. 53, 54, and 61 to the lower three places of the respective symbols.

[0370] Unlike the structure of the ninth embodiment, the drain socket 1360 of the eleventh embodiment has a non-separable structure of the base member 380 and the main body member 371. The drain socket 1360 accordingly includes two members, that is, a main body member 1371 and an inner drain conduit socket member 1372 attached to the main body member 1371.

[0371] As shown in FIG. 63, the main body member 1371 defines a main conduit 1373 as the flow path of reserved water RW, cleansing water, and excrement. The main body member 1371 corresponds to the first flow path defining member in the claims. Attachment of the inner drain conduit socket member 1372 to the main body member 1371 extends the main conduit 1373 toward the downstream side to a specific position in the drain conduit 1390 below the floor surface FL. The inner drain conduit socket member 1372 corresponds to the second flow path defining member in the claims.

[0372] Like the tenth embodiment, the inner drain conduit socket member 1372 is constructed by a combination of two members, a first cylindrical section 1372 b of a quasi-cylindrical shape with a second cylindrical section 1372 c of a cylindrical shape. More specifically, the inner drain conduit socket member 1372 is provided by joining the upper end of the second cylindrical section 1372 c with the lower end of the first cylindrical section 1372 b.

[0373] Referring to FIG. 63, the first cylindrical section 1372 b defines an expanded conduit 1375 having a greater pipeline diameter than that of the main conduit 1373 as the flow path communicating with the main conduit 1373. The second cylindrical section 1372 c defines a straight line conduit 1376 having practically the same diameter as that of the main conduit 1373 as the flow path communicating with the expanded conduit 1375. The inner drain conduit socket member 1372 is provided with a non-restricted element 1372 p, a first restriction 1372 q, and a second restriction 1372 r like the tenth embodiment.

[0374] A different technique from that of the tenth embodiment is applied for attachment of the inner drain conduit socket member 1372 to the main body member 1371 as discussed below. A ring-shaped projection 1379 is formed around the main conduit 1373 defined by the main body member 1371. A fringe 1379 a is formed integrally with the ring-shaped projection 1379 on the inner circumferential wall of the ring-shaped projection 1379. The first cylindrical section 1372 b of the inner drain conduit socket member 1372 is bonded to this fringe 1379 a. The whole length of the drain socket is accordingly a distance 15 between the top face of a descending pathway fitting element 1371 a and the lower end of the second cylindrical section 1372 c of the inner drain conduit socket member 1372 as shown in FIG. 63.

[0375] The drain conduit 1390 rising from the floor surface FL is inserted into the fringe 1379 a, to which the inner drain conduit socket member 1372 is bonded. The drain conduit 1390 is bonded to the inner circumferential wall of the ring-shaped projection 1379. The bonding connects the drain socket 1360 with the drain conduit 1390.

[0376] Marks representing the optional cutting positions of the first cylindrical section 1372 b are curved on the first cylindrical section 1372 b of the inner drain conduit socket member 1372 as shown in FIG. 64. FIG. 64 shows the appearance of the first cylindrical section 1372 b. Three scale lines are curved on the outer circumferential face of the first cylindrical section 1372 b at pitches of 20 mm along the height.

[0377] Numerical values representing the lengths of the first cylindrical section 1372 b extended below the floor surface FL in the state of attachment of the first cylindrical section 1372 b to the fringe 1379 a are curved in the vicinity of the respective scale lines. More specifically, numerical values of 40 mm to 100 mm are shown by the unit of 20 mm in the example of FIG. 64. For example, when the whole first cylindrical section 1372 b without cutting is bonded to the fringe 1379 a, a lower end 1372 g of the first cylindrical section 1372 b is located at a position below the floor surface FL by 100 mm. The numerical values 40 mm, 60 mm, and 80 mm respectively represent the length of the first cylindrical section 1372 b extended below the floor surface FL when the first cylindrical section 1372 b is cut at the position of the scale line above each numerical value. For example, when the first cylindrical section 1372 b cut at the position of the scale line of 60 mm is bonded to the fringe 1379 a, the lower end 1372 g of the first cylindrical section 1372 b is located below the floor surface FL by 60 mm. Other numerical values may alternatively be used to represent the lengths of the first cylindrical section 1372 b and the second cylindrical section 1372 c extended below the floor surface FL.

[0378] Each of the numerical values is shown on the side face of the remaining member, which is cut at each scale line and used as the first cylindrical section 1372 b. This arrangement enables the user to check the length of the first cylindrical section 1372 b in the process of attachment of the first cylindrical section 1372 b after cutting. The first cylindrical section 1372 b without cutting is illustrated in FIG. 63.

[0379]FIG. 65 shows attachment of the inner drain conduit socket member 1372 to the fringe 1379 a, where the first cylindrical section 1372 b is cut at the scale line of 60 mm and is joined with the second cylindrical section 1372 c. As shown in FIG. 65, since the bonded first cylindrical section 1372 b has been cut, a distance 16 between the top face of the descending pathway fitting element 1371 a and the lower end of the second cylindrical section 1372 c of the inner drain conduit socket member 1372 is shorter than the distance 15 shown in FIG. 63. The length of the inner drain conduit socket member 1372 extended below the floor surface FL is the sum of 60 mm or the length of the first cylindrical section 1372 b and the length of the second cylindrical section 1372 c.

[0380] In the drain socket 1360 of the eleventh embodiment discussed above, the length of the inner drain conduit socket member 1372 extended below the floor surface FL is varied by cutting the first cylindrical section 1372 b. This arrangement enables the flow path of the drain socket 1360 to be changed to an arbitrary length. The optional cutting positions of the first cylindrical section 1372 b are shown by the scale lines. This ensures the smooth cutting work. The numerical value is shown in the vicinity of each scale line to represent the length of the first cylindrical section 1372 b, which is cut at the scale line and extended below the floor surface FL. The adequate length of the inner drain conduit socket member 1372 is thus specified to prevent the potential interference with the drain conduit 1390 rising from the floor surface FL.

[0381]FIG. 66 shows a modified structure of the first cylindrical section 1372 b. A first cylindrical section 2372 b shown in FIG. 66 does not have the non-restricted element 1372 p of the eleventh embodiment, but has a first restriction 2372 q having a cross sectional area gradually decreasing from the start end to the terminal end of the first cylindrical section 2372 b.

[0382] Three scale lines are curved at pitches along the height on the outer circumferential face of the first cylindrical section 2372 b as marks representing the optional cutting positions of the first cylindrical section 2372 b. A numerical value representing the inner diameter of the first cylindrical section 2372 b at the cutting position of each scale line is curved above the scale line. In the example of FIG. 66, numerical values of 40 mm, 45 mm, and 50 mm are shown. Each of the numerical values is shown on the side face of the remaining member, which is cut at each scale line and used as the first cylindrical section 2372 b. This arrangement enables the user to check the inner diameter at the end of the first cylindrical section 2372 b in the process of attachment of the first cylindrical section 2372 b after cutting.

[0383] Attachment of the first cylindrical section 2372 b cut at an arbitrary scale line to the fringe 1379 a shown in FIG. 63 regulates the degree of restriction in the first cylindrical section 2372 b. For example, cutting at the position of the inner diameter of 50 mm shortens the length of the first cylindrical section 2372 b and weakens the retaining power applied to the reserved water RW or the flow of cleansing water passing through the first cylindrical section 2372 b. The first cylindrical section 2372 b gives the desired retaining power in the drain socket 1360 according to the performance of the toilet, to which the drain socket 1360 is attached.

[0384] In the tenth and the eleventh embodiments discussed above, the inner drain conduit socket member 372 or 1372 is constructed by the two separate members, the first cylindrical section 372 b or 1372 b and the second cylindrical section 372 c or 1372 c. The inner drain conduit socket member 372 or 1372 may, however, be constructed by one integral member.

[0385] The inner drain conduit socket member 372 or 1372 may otherwise be constructed by three or more separator members. In the structure of the tenth embodiment, the fringe 1379 a is formed integrally with the ring-shaped projection 1379. In one possible modification, a member equivalent to the fringe 1379 a is formed separately from the ring-shaped projection 1379, and a combination of the fringe-like member 1379 a, the first cylindrical section 1372 b, and the second cylindrical section 1372 c is attached as the inner drain conduit socket member 1372 to the ring-shaped projection 1379. Such modification allows the position of attachment of the fringe-like member 1379 a to the ring-shaped projection 1379 to be freely changed. For example, when the position of attachment of the fringe-like member 1379 a to the ring-shaped projection 1379 is specified according to the rising height of the drain conduit 1390 from the floor surface FL, the drain conduit 1390 is tightly fitted in a space defined by the inner circumferential wall of the ring-shaped projection 1379 and the fringe-like member 1379 a. This arrangement assures successful attachment of the drain socket 1360 without cutting the drain conduit 1390, which may have various rising heights.

[0386] In the tenth and the eleventh embodiments discussed above, the bonding technique is applied to attach the inner drain conduit socket member 372 or 1372 to the main body member 371 or 1371. Any adequate technique other than bonding, for example, fitting or engagement, may be applied to change the position of the inner drain conduit socket member 372. In one modified structure, the inner drain conduit socket member 372 is slidably fitted in the circumferential wall of the first ring-shaped recess 364.

[0387] The degrees of restriction provided in the main conduit 373 or 1373 and the expanded conduit 375 or 1375 are specified arbitrarily according to the layout of the flow path of cleansing water. The straight line conduit 376 or 1376 may have an additional restriction. In the above embodiments, the center of the main conduit 373 or 1373 may be eccentric to the center of the expanded conduit 375 or 1375.

[0388] In the above embodiments, the numerical values representing the ‘lengths of the inner drain conduit socket member 1372 cut at the respective scale lines and extended below the floor surface FL’ or the numerical values representing the ‘inner diameters of the inner drain conduit socket member 1372 at the respective cutting positions’ are used as the numerical values curved on the side face of the inner drain conduit socket member 1372. The curved numerical values may otherwise be any values or information based on the different conditions of the installation fields or based on the diverse types of toilets.

[0389] For example, it is generally thought that the distance from the floor surface FL, on which the toilet is installed, to the drain conduit horizontally laid under the floor surface FL is about 800 mm on the first floor of a house and about 100 mm to 200 mm on the second floor. The numerical values representing the ‘lengths of the inner drain conduit socket member 1372 cut at the respective scale lines and extended below the floor surface FL’ are shown on the side face of the inner drain conduit socket member 1372. The worker who installs the toilet then does not hesitate to select the cutting position among the multiple marks but readily determines the adequate cutting position according to the floor on which the toilet is installed. This arrangement thus ensures the smooth and adequate attachment of the drain socket.

[0390] The siphon action-type toilets of different models or different product numbers may have different quantities of cleansing water. The product numbers of toilets may thus be shown in the vicinity of the respective scale lines, instead of the numerical values representing the ‘lengths of the inner drain conduit socket member 1372 cut at the respective scale lines and extended below the floor surface FL’ or the numerical values representing the ‘inner diameters of the inner drain conduit socket member 1372 at the respective cutting positions’. This arrangement enables the worker who installs the toilet to readily determine the adequate cutting position based on the product number of the toilet, while ensuring the desired water retaining state in the drain socket by taking into account the difference in flow rate of cleansing water among the toilets.

[0391] Packing the inner drain conduit socket member 372 or 1372 with the toilet effectively prevents the potential delay of installation due to the missing inner drain conduit socket member 372 or 1372 or the loss of the inner drain conduit socket member 372 or 1372 in the field. Single sale of the inner drain conduit socket member 372 or 1372 is preferable in the case where the state of the drain conduit 390 or the type of the toilet 310 is not changeable.

[0392] The ninth through the eleventh embodiments may be modified as discussed below.

[0393] For example, in the drain socket 360 or 1360 of the above embodiments, the lower end of the descending pathway 333 or 1333 is placed on the setting plane 371 b of the descending pathway fitting element 371 a. The lower end of the descending pathway 333 or 1333 is, however, not required to be in contact with the setting plane 371 b. The only requirement is that the lower end of the descending pathway 333 or 1333 is located in the range of the height of the descending pathway fitting element 371 a. This is because the load of the toilet 310 or 1310 is not applied to the setting plane 371 b but is received by the floor surface FL.

[0394] The drain sockets 360 and 1360 of the above embodiments are applicable to the lead drain conduits 390 and 1390. In this case, the drain socket 360 or 1360 is connected to the drain conduit 390 or 1390 via an adaptor, which is separately provided to allow connection with lead pipes.

[0395] In the above embodiments, the drain conduit 390 rises from the floor surface FL to construct the floor drainage system. The technique of the present invention is also applicable to the wall drainage system, where the drain conduit 390 is extended from the wall surface of the lavatory with the toilet 310. There are mainly two variations of toilets corresponding to the different building conditions. One is an S-trap type, where the end of a drain conduit faces the floor. The other is a P-trap type, where the end of the drain conduit faces the wall. Different models of the same P trap-type toilets may have different distances between the end of the drain conduit and the wall surface. In the wall drainage system, the length of the drain conduit extended from a rising pipe behind the wall is varied in different places, as in the case of the floor drainage system. A joint member that joins the drain conduit extended from the wall with the end of the drain conduit in the P-trap type toilet preferably has a variable overall length. This allows the common joint member and enhances the application of the lavatory.

[0396] The above embodiments regard the siphon jet action-type toilets, but the technique of the present invention is applicable to other types of toilets. The other types of toilets include the siphon action-type toilets that induce the siphon action without the jet flow of cleansing water from the jet nozzle and the washout-type toilets that do not utilize the siphon action but flow out excrement and reserved water by the force of cleansing water. In the washout-type toilet having a vertically curved drain conduit, the water level in the drain conduit approaches to a full level in the process of cleansing the toilet, and a phenomenon similar to the siphon action may occur. The drain socket 8360 or 1360 of the above embodiment is preferably applied in such cases. The retaining position of reserved water RW or cleansing water is arbitrarily regulated by changing the position of attachment of the inner drain conduit socket member 8372 or 1372. This heightens the sucking force of the reserved water RW or cleansing water toward the drain conduit 8390 or 1390 and thereby enhances the cleansing power.

[0397] The above embodiments regard application of the technique of the present invention to the siphon jet action-type toilets or other toilets. The technique of the present invention is also applicable to combinations of these toilets with other devices and members. Examples of such application include sanitary cleansing appliances with the functional toilet seat to attain diverse functions like personal cleansing and heating, lavatory furniture including lavatory cabinets and wash basins, and lavatories including structural materials, like wall materials, floor materials, and ceiling materials.

[0398] The following describes twelfth through fourteenth embodiments.

[0399]FIG. 67 is a vertical sectional view illustrating a siphon jet action-type toilet 410 in a twelfth embodiment of the present invention. The siphon jet action-type toilet 410 makes cleansing water ejected from a jet nozzle 422 discussed later to induce the siphon action.

[0400] Referring to FIG. 67, the toilet 410 has a bowl 420 to receive excrement therein. A peripheral wall of the bowl 420 has a water-submerged surface 423 that is in contact with reserved water RW even in a non-cleansing time of the toilet 410 and an exposed surface 424 that is not in contact with the reserved water RW in the non-cleansing time of the toilet 410.

[0401] The jet nozzle 422 is disposed in a recess 426 on the bottom of the bowl 420 to substantially face a suction opening 425 of a siphon trap conduit. The jet nozzle 442 is connected to a jet supply nozzle 445, which is an inlet port of cleansing water to the jet nozzle 422, via a jet supply conduit 446 curved to surround the bowl 420 in the toilet. A jet of cleansing water from the jet nozzle 422 enters a siphon trap of and after the suction opening 425 without any significant energy loss, based on the positional relation between the jet nozzle and the suction opening of the siphon trap. This arrangement enables the conduit to be quickly filled with water and instantly induces the siphon action.

[0402] A water tank WT is set behind the toilet 410 to feed a supply of cleansing water to the bowl 420 for cleansing the toilet. The toilet 410 is provided with a cleansing water supply apertures 440, into which the supply of cleansing water from the water tank is flown through a water supply pipe SL, and a cleansing water supply conduit 441 disposed below the cleansing water supply aperture 440 as the flow path of cleansing water. The cleansing water supply conduit 441 divisionally forms a retention space 441 a as a space interposed between the jet supply conduit 446 for ejecting a jet of cleansing water towards the bowl and a lower end of a drain conduit of the water tank WT. In response to each flushing action, cleansing water released from the drain conduit is flown into the retention space 441 a and is ejected from the jet nozzle 422 via the jet supply nozzle 445 and the jet supply conduit 446. After the retention space 441 a is filled with water, the cleansing water in the retention space 441 a is flown out to rim supply conduits 443 via a branch hole 442 disposed above the retention space 441 a and ejected from a rim nozzle 444 formed on a lower end of a rim member 421.

[0403] The drainage mechanism including the siphon trap is discussed. As illustrated, the siphon trap includes a connection pathway 431 that is curved in an oblique upward direction from the suction opening 425 in the recess 426 as the excrement reservoir, an ascending pathway 432 that is extended in the curving direction of the connection pathway 431 and is curved in a lateral direction, and a descending pathway 433 that is curved downward from the lateral extension and functions as a first descending conduit.

[0404] The descending pathway 433 includes an expanded section 433 a having a greater pipeline diameter and a tapered end 433 b having a narrower opening area than that of the expanded section 433 a. The expanded section 433 a and the tapered end 433 b of the descending pathway 433 function to temporarily retain the flow of cleansing water, so that the descending pathway 433 induces the siphon action. The end of the descending pathway 433 is connected to a drain conduit 490, which rises upward from the floor surface FL at the position of installation of the toilet, via a resin drain socket 470 functioning as a second descending conduit.

[0405] These flow paths are formed integrally with the toilet 410 made of pottery by utilizing a plaster or resin mold, although the flow paths may be made of a different material separately from the toilet 410. For example, all or part of the flow paths may be made of another material like resin and connected to the suction opening 425.

[0406] The drain socket 470 has a socket main body 471 that is located on the floor surface FL of the lavatory and fixed to the floor surface FL with bolts, and a conduit defining member 473 that defines a socket conduit 472 for leading the flow of cleansing water, which has passed through the siphon trap, to the drain conduit 490. The conduit defining member 473 has a spiral recess 474 that surrounds the socket conduit 472 in a spiral form. The socket conduit 472 has a diameter substantially equal to that of the tapered end 433 b.

[0407] The socket main body 471 has a descending pathway fitting element 471 a that receives the lower end of the descending pathway 433 therein, and a drain conduit fitting element 475 that receives the upper end of the drain conduit 490 inserted upward and fitted therein. The drain conduit fitting element 475 receives the drain conduit 490 fitted therein and thereby positions the drain socket 470 relative to the drain conduit 490. Since the lower end of the conduit defining member 473 is located below the upper end of the drain conduit 490, the flow of cleansing water passing through the conduit defining member 473 does not leak from the upper end of the drain conduit 490.

[0408] Both the socket main body 471 and the conduit defining member 473 of the drain socket 470 are resin molded objects and are formed separately from the toilet 410 or more specifically from the descending pathway 433, although they may be integrated with the descending pathway 433 (that is, with the siphon trap). In the integrated structure with the descending pathway 433, a conduit like the socket conduit 472 with the spiral recess 474 is formed in the descending pathway 433 to communicate with the expanded section 433 a across the tapered end 433 b. In another modification, the siphon trap of the toilet 410 does not have the siphon action inducing mechanism like the tapered end 433 b, while the drain socket 470 connecting with the siphon trap has the siphon action inducing mechanism like the tapered end 433 b, in addition to the socket main body 472 and the conduit defining member 473. The polyvinyl chloride resin, which is the material of the drain conduit 490, may be used as the material of the resin molded objects of the socket main body 471 and the conduit defining member 473. Any of diverse resins, such as ABS resin, PP (polypropylene), PE (polyethylene), PPS (polyphenylene sulfide), MA (acrylic), and POM (polyacetal), is also applicable.

[0409] As illustrated, in the toilet 410 before a flushing action, the reserved water RW in the connection pathway 431, the ascending pathway 432, and the bowl 420 reaches the standard height of water level WL. The reserved water RW effectively prevents a reverse flow of offensive odor and invasion of vermin from the drainage mechanism to the bowl 420.

[0410] The reserved water RW includes water kept in the bowl 420 before the suction opening 425 (hereinafter this water is referred to as the bowl storage water or the sealing water), water kept in the connection pathway 431 and the ascending pathway 432 after the suction opening 425 (hereinafter this water is referred to as the flow path storage water), and water kept in the lower portion of the retention space 441 a and the jet supply conduit 446 of the toilet 410 (hereinafter this water is referred to as the jet storage water). As shown in FIG. 67, the flow path storage water is kept in only one place along the connection pathway 431 or the ascending pathway 432, out of the flow path of sanitary sewage including the connection pathway 431, the ascending pathway 432, and the descending pathway 433. Here the ‘sanitary sewage’ means dirt water mixed with excrement like stool and urine and paper.

[0411] The water level WL generally depends upon the height of a weir 434, which is the highest position of the lower inner wall of the ascending pathway 432. The lower portion of the retention space 441 a, the jet supply nozzle 445, and the jet supply conduit 446 are located below the weir 434 in the toilet 410 as shown in FIG. 67. In the stationary state of the toilet 410, the jet storage water is kept at the above water level in the lower portion of the retention space 441 a and the jet supply conduit 446. The lowered height of the weir 434 lowers the water level of the reserved water RW and decreases the total quantity of the bowl storage water, the flow path storage water, and the jet storage water.

[0412] The following describes the process of discharging the sanitary sewage and excrement by means of the drainage mechanism having the above construction. A release of cleansing water from the water tank WT first flows into the retention space 441 a. The potential energy of the released cleansing water works as kinetic energy and causes the jet storage water in the jet supply conduit 446 to flow into the bowl storage water (sealing water) in the bowl 420. This starts a jet of cleansing water from the jet nozzle 422 toward the trap described above. While the release of cleansing water continues, the released cleansing water is continuously jetted from the jet nozzle 422 by means of its potential energy. In the initial stage of the water jet action, the retention space 441 a is filled with the new release of cleansing water. In the subsequent stage, the release of cleansing water passes through the branch hole 442 and is ejected out of the rim nozzle 444.

[0413] When the cleansing water is ejected out to the bowl 420, the water level in the ascending pathway 432 rises and the water reaches its full level at the curved joint portion of the ascending pathway 432 and the descending pathway 433 (hereinafter simply referred to as the curved portion). The flow of cleansing water then passes through the descending pathway 433, and is temporarily retained in the expanded section 433 a on the lower end of the descending pathway 433. The trap conduit is then filled with cleansing water to form the siphon pipeline. There is a pressure difference between the cleansing water of the siphon pipeline and the reserved water in the bowl 420. This pressure difference generates a downward pulling force, which causes the excrement together with the cleansing water (sanitary sewage) in the siphon trap (that is, in the ascending pathway 432 and the connection pathway 431) and the cleansing water (sanitary sewage) in the bowl to be vigorously led into the drain conduit 490. This process induces the siphon action.

[0414] The behaviors of cleansing water after induction of the siphon action are discussed below. FIG. 68 shows behaviors of cleansing water passing through the siphon trap and the socket conduit 472.

[0415] After induction of the siphon action, the flow of cleansing water passes through the expanded section 433 a and the socket conduit 472 as shown by the open arrow in FIG. 68(a). Part of the cleansing water enters the spiral recess 474 surrounding the socket conduit 472 to be retained therein. The cleansing water retained in the spiral recess 474 is flown down in a spiral form through the spiral recess 474 as shown by the dotted line. The cleansing water retained in the spiral recess 474 is alternatively flown down by its dead weight through the recess openings and joins the flow of cleansing water shown by the open arrow.

[0416] In the terminal stage of the siphon action when the supply of a predetermined flow rate of cleansing water from the water tank WT and the jet of cleansing water from the jet nozzle are practically terminated, the flow rate of cleansing water passing through the siphon trap and reaching the socket conduit 472 is reduced. In this state, the flow rate of cleansing water directly passing through the socket conduit 472 (hereinafter such cleansing water is referred to as the direct flow of cleansing water as a matter of convenience) is lowered as shown in FIG. 68(b). The retained cleansing water is present in the spiral recess 474 and is flown down in a spiral form along the spiral recess 474 or joins the direct flow of cleansing water. The retained cleansing water is accordingly supplementary cleansing water added to the direct flow of cleansing water. This increases the total flow rate of cleansing water passing through the midd1e or the end of the socket conduit 472. The ratio of the occupation area of cleansing water to the cross section of the socket conduit 472 is greater than the ratio in the conventional structure without the spiral recess 474. The cleansing water having the greater occupation area effectively prevents invasion of the air from the drain conduit 490. Even in the terminal stage of the siphon action having the reduced flow rate of cleansing water, this arrangement extends the effective siphon action, so as to enhance the suction efficiency of the reserved water in the bowl in the terminal stage of the siphon action and heighten the reliability of suction and discharge of floating excrement.

[0417] The supplementary cleansing water is supplied to the direct flow of cleansing water from the respective steps of the spiral recess 474. The arrangement ensures supply of the supplementary cleansing water to the direct flow of cleansing water and thereby extends the effective siphon action. This enhances the suction efficiency of the reserved water in the bowl in the terminal stage of the siphon action and heightens the reliability of suction and discharge of floating excrement.

[0418] The spiral recess 474 is provided immediately below the tapered end 433 b of the connection pathway 431 that induces the siphon action. Namely the cleansing water is supplemented in the vicinity of the place of induction of the siphon action. This ensures extension of the effective siphon action and enhances the reliability.

[0419] Part of the direct flow of cleansing water is led into the spiral recess 474 as the supplementary cleansing water. This arrangement does not require any special water system for supplement of cleansing water, thus simplifying the construction while not increasing the total flow rate of cleansing water used for cleansing the toilet.

[0420] The spiral flow of cleansing water in the spiral recess 474 swirls along the socket conduit 472. The swirl of cleansing water also effectively prevents invasion of the air from the drain conduit 490. This arrangement further enhances the suction efficiency in the terminal stage of the siphon action and heightens the reliability of suction and discharge of floating excrement.

[0421] In the structure of this embodiment, the socket conduit 472 is formed to have the spiral recess 474. One possible modification may use a spiral-shaped plate, which is inserted in and attached to the socket conduit 472.

[0422] One modification of the above embodiment is discussed here. FIG. 69 illustrates a modified structure of the drain socket 470. As illustrated, the drain socket 470 of the modified example has a plurality of ring-shaped recesses 474 a, which are extended outside the socket conduit 472 at preset intervals. Part of the flow of cleansing water is temporarily retained in the respective ring-shaped recesses 474 a and supplied to the direct flow of cleansing water by its dead weight. In this modified structure, the cleansing water retained in the respective ring-shaped recesses 474 a joins the direct flow of cleansing water in the socket conduit 472, thus attaining the effects discussed above.

[0423] The following describes still another embodiment. FIG. 70 illustrates a drain socket 1470 in a thirteenth embodiment. As illustrated, the drain socket 1470 of this embodiment has a socket main body 1471 for fixation to the floor surface. An upstream socket conduit 1472 and a downstream socket conduit 1474, which are eccentric to each other, are formed inside the socket main body 1471 to lead the flow of cleansing water to the drain conduit 490. The drain socket 1470 further includes a step 1475, which faces the lower end of a conduit defining member 1473 that defines the upstream socket conduit 1472, and a retention chamber 1476 that is disposed above the step 1475 and surrounds the conduit defining member 1473. The upstream socket conduit 1472 and the downstream socket conduit 1474 have diameters virtually identical with the diameter of the tapered end 433 b.

[0424] The descending pathway 433 is fitted in a descending pathway fitting element 1471 a on the upper end of the socket main body 1471, and the socket main body 1471 is fixed to the floor surface. A sealing member 1477 is disposed on the upper end of the drain conduit 490 for sealing. In the drain socket 1470, the lower end of the downstream socket conduit 1474 is located below the upper end of the drain conduit 490. This arrangement effectively prevents leakage of cleansing water from the upper end of the drain conduit 490. This drain socket 1470 is composed of any resin mentioned above, for example, the polyvinyl chloride resin or the ABS resin.

[0425] In the drain socket 1470, the flow of cleansing water passing through the upstream socket conduit 1472 hits against the step 1475 to change its flow direction as shown by the arrow, and is flown into the downstream socket conduit 1474. The retention chamber 1476 is located above the step 1475 as an extension. This structure combines with the step 1475, which changes the flow direction, to temporarily retain the flow of cleansing water and contribute to induction of the siphon action. In the toilet 410 with the drain socket 1470 attached thereto, the siphon action is induced at two different positions, that is, at the tapered end 433 b and at the step 1475 in the drain socket 1470. This effectively enhances the sucking force of the reserved water and the suction efficiency. Since the siphon action is also induced in the drain socket 1470, attachment of this drain socket 1470 to the toilet 410 having the straight end of the siphon trap, that is, the straight end of the descending pathway 433, effectively induces the siphon action.

[0426] The following describes the behaviors of cleansing water in the drain socket 1470. The flow of cleansing water passing through the upstream socket conduit 1472 (that is, the direct flow of cleansing water) by induction of the siphon action hits against the step 1475 and is flown into the downstream socket conduit 1474. Part of the cleansing water is flown into the retention chamber 1476 by means of the pressure for inducing the siphon action, the water head (head difference) from the water surface of the reserved water in the bowl 420. The air, which is present in the retention chamber 1476, is compressed by the pressure of cleansing water. The flow rate of cleansing water corresponding to the compressed air is accordingly retained in the retention chamber 1476. Namely this retention chamber 1476 functions as a kind of accumulator.

[0427] In the terminal stage of the siphon action, the flow rate of cleansing water that passes through the upstream socket conduit 1472 and is flown into the downstream socket conduit 1474 is reduced, while the pressure of cleansing water that blocks the lower end of the retention chamber 1476 is lowered. Under such conditions, the cleansing water retained in the retention chamber 1476 is flown out of the retention chamber 1476, due to its water pressure and dead weight and increases the flow rate of cleansing water passing through the downstream socket conduit 1474. The ratio of the occupation area of cleansing water to the cross section of the downstream socket conduit 1474 is greater than the ratio in the conventional structure that does not have the retention chamber 1476 and only changes the flow direction of cleansing water by the step 1475. The cleansing water having the greater occupation area effectively prevents invasion of the air from the drain conduit 490. The drain socket 1470 of the thirteenth embodiment thus exerts the similar effects to those of the embodiments discussed above.

[0428] In the drain socket 1470, the cleansing water is supplied from the retention chamber 1476, which surrounds the upstream socket conduit 1472, around the circumference of the upstream socket conduit 1472 on the lower end thereof. This readily increases the total flow rate of cleansing water.

[0429] The drain socket 1470 of the thirteenth embodiment has the retention chamber 1476, which surrounds the upstream socket conduit 1472. In one possible modification, the retention chamber may be disposed on one side of the upstream socket conduit 1472. FIG. 71 shows a drain socket 1470A in a modified example. The drain socket 1470A has a projection 1478 that is provided in a neighborhood of the lower end of the upstream socket conduit 1472, and a retention chamber 1476 that is disposed on the side facing the projection 1478. In this drain socket 1470A, the flow of cleansing water hits against the projection 1478 and changes its flow direction to enter the retention chamber 1476 as shown by the arrows. The drain socket 1470A of the modified example thus attains supply of cleansing water from the retention chamber 1476, as in the structure of the thirteenth embodiment discussed above.

[0430] The following describes a fourteenth embodiment. FIG. 72 illustrates a drain socket 2470 in the fourteenth embodiment. As illustrated, the drain socket 2470 of this embodiment has a socket main body 2471 for fixation to the floor surface. A socket conduit 2472 is formed inside the socket main body 2471 for leading the flow of cleansing water to the drain conduit 490. The drain socket 2470 also has a restriction mechanism that narrows and adjusts the pipeline diameter of the socket conduit 2472. The restriction mechanism includes a pair of conduit restriction members 2473 that are arranged in the socket conduit 2472 to face each other, an actuator 2474 that advances and retreats the conduit restriction member 2473 in the socket conduit 2472, and a non-illustrated actuator controller.

[0431] The conduit restriction members 2473 are made of a resilient material having good water resistance and durability, such as a rubber or an elastomer, and are fixed water-tightly to a wall 2475 of the socket conduit 2472. The actuator 2474 receives an instruction output from the actuator controller and advances the conduit restriction members 2474 in a curved shape into the socket conduit 2472 or retreats the conduit restriction members 2474 toward the wall of the socket conduit 2472. The actuator controller detects the terminal stage of the siphon action and drives and controls the actuator in response to the detection, based on the elapse of time since a start of cleansing the toilet and a variation in pressure in the socket conduit 2472.

[0432] When cleansing of the toilet starts in response to an operation of a non-illustrated hand1e or button, the actuator controller gives an advance instruction to the actuator 2474 and drives the actuator 2474 to advance the conduit restriction members 2473 into the socket conduit 2472 as illustrated. Such movement narrows the socket conduit 2472 and thereby restricts passage of the cleansing water through the socket conduit 2472. Under such restrictions, the siphon action is induced at the tapered end 433 b of the descending pathway 433, while the flow of cleansing water passes through the socket conduit 2472. This arrangement thus ensures sufficient suction of reserved water and excrement without any specific troubles. The narrowed pipeline by the advance of the conduit restriction members 2473 does not have any troubles in transport of excrement. The illustrated advance position of the conduit restriction members 2473 may be set as the position of the origin of the restriction mechanism. In this case, the above process of driving the actuator is not required.

[0433] In response to detection of the terminal stage of the siphon action, for example, based on the elapse of time, the actuator controller gives a retreat instruction to the actuator 2474 and drives the actuator 2474 to retreat the conduit restriction members 2473 toward the wall surface of the socket conduit 2472. This expands the socket conduit 2472 to the original state and relieves the restriction of passage of cleansing water due to the narrowed socket conduit 2472, thus increasing the flow rate of cleansing water passing through the socket conduit 2472 downstream the restriction mechanism. In the terminal stage of the siphon action, the occupation area of cleansing water in the socket conduit 2472 downstream the restriction mechanism increases to extend the effective siphon action and enhance the suction efficiency of the reserved water in the bowl. This arrangement thus attains the similar effects to those of the embodiments discussed above.

[0434] The twelfth through the fourteenth embodiments may be modified as discussed below.

[0435] In the above embodiments, a low tank connecting with the toilet is applied for the water tank. A diversity of tanks other than the low tank, for example, corner and front installation tanks that are connected to the toilet via a wash pipe and located at the wall of the lavatory, may be applicable for the water tank. In such cases, the water tank may be a high tank located at a high position.

[0436] The above embodiments regard application of the technique of the present invention to the siphon jet action-type toilet 410 or the siphon action-type toilet. The technique of the present invention is also applicable to combinations of these toilets with other devices and members. Examples of such application include sanitary cleansing appliances with the functional toilet seat to attain diverse functions like personal cleansing and heating, lavatory furniture including lavatory cabinets and wash basins, and lavatories including structural materials, like wall materials, floor materials, and ceiling materials.

[0437] The following describes a fifteenth embodiment.

[0438]FIG. 73 is a vertical sectional view illustrating a siphon jet action-type toilet 610 in a fifteenth embodiment of the present invention. FIG. 74 shows the top face of the toilet 610. The toilet 610 makes cleansing water ejected from a jet nozzle 622 discussed later and thereby induces the siphon action. Respective constituents of the toilet 610 are discussed below with reference to FIGS. 73 and 74.

[0439] The toilet 610 includes a pottery toilet body 611, a resin drain socket 670, and a water tank. The drain socket 670 connects a drainage port of a drain conduit 630 included in the toilet body 611 with a drain conduit P protruded from the floor surface FL.

[0440] The toilet body 611 has a bowl 620 to receive excrement therein. A peripheral wall of the bowl 620 has a water-submerged surface 623 that is in contact with reserved water RW even in a non-cleansing time of the toilet 610 and an exposed surface 624 that is not in contact with the reserved water RW in the non-cleansing time of the toilet 610.

[0441] Referring to FIG. 74, the jet nozzle 622 is connected to a jet supply nozzle 645, which is a water inlet, via a jet supply conduit 646 curved inside the toilet. The jet nozzle 622 is located to substantially face a drainage port 625 across a recess 626 as shown in FIG. 73. Energy of cleansing water is thus transmitted to a drainage mechanism of and after the drainage port 625 without any significant waste. This leads to instant induction of the siphon action.

[0442] The toilet 610 is provided with a supply mechanism for supplying water to the bowl 620 and a drainage mechanism for discharging excrement in the bowl 620 toward the drain conduit P.

[0443] The supply mechanism is discussed first. A cleansing water supply aperture 640, which is a hole connecting with a water supply pipe SL of a water tank WT, is provided behind the toilet 610. A cleansing water supply conduit 641, which defines a flow path of cleansing water led from the water tank WT, is disposed inside the toilet 610 along a passage from the cleansing water supply aperture 640 towards the bowl 620. The cleansing water supply conduit 641 divisionally forms a retention space 641 a as a space interposed between the jet supply conduit 646 for ejecting a jet of cleansing water towards the bowl 620 and a lower end of the water supply pipe of the water tank WT. In response to each flushing action, cleansing water fed from the water supply pipe SL is flown into the retention space 641 a and is flown out to rim supply conduits 643 via the jet supply conduit 646 and a branch hole 642 discussed later.

[0444] Water (cleansing water) kept in the tank is pressed by free fall and is fed at once to the cleansing water supply conduit 641. The retention space 641 a, the lower oblique division of the cleansing water supply conduit 641, is filled with water after start of each flushing action. Part of the cleansing water is supplied from the branch hole 642 to the rim supply conduits 643. The flow of cleansing water supplied to the rim supply conduits 643 is ejected from water outlets 644 (see FIG. 74) formed in a rear face of a rim member 621.

[0445] As shown in FIG. 74, there are five different types of water outlets 644 having various shapes, that is, a large aperture 644 a of 7 mm in diameter, medium apertures 644 b of 4 mm in diameter, small apertures 644 c of 3 mm in diameter, and quasi rectangular slots 644 d and 644 e, provided on the rear face of the rim member 621. The water outlets 644 are typically formed in the course of production of the rim member 621. A distributor with water outlets may otherwise be attached to the rear face of the rim member 621.

[0446] The cleansing water pressed forward in the toilet 610 is led into the left and right rim supply conduits 643, is distributed according to the opening diameters of the water outlets 644 and the pressing force of cleansing water, and is ejected out of the respective water outlets 644 a through 644 e. The cleansing water of the large pressing force is ejected from the slot 644 d, which is formed on the right back side close to the branch hole 642 in the rear face of the rim member 21, toward the exposed surface 624 on the slightly left side in the front portion of the toilet. A large quantity of the clockwise flow of cleansing water through the rim supply conduits 643 is ejected from the slot 644 e, which is formed on the slightly right side position in the front portion of the toilet 610, toward the exposed surface 624 in the rear left portion of the toilet 610. The cleansing water ejected from the slots 644 d and 644 e makes a main stream and gives the clockwise swirling force to the cleansing water ejected out of the water outlets 644. The swirling force is transmitted to reserved water RW in the bowl 620. This makes a clockwise swirl flow of water in the bowl 620.

[0447] The cleansing water reaching the retention space 641 a goes into the jet supply nozzle 645, which is formed in the side wall of the retention space 641 a. This leads to supply of cleansing water into the jet supply conduit 646. The cleansing water supplied to the jet supply conduit 646 is jetted out of the jet nozzle 622. When the retention space 641 a is filled with the new supply of cleansing water, the cleansing water is led to the rim supply conduits 643 via the branch hole 642 and is ejected out of the water outlets 644 of the rim.

[0448] The drainage mechanism has the construction discussed below. As shown in FIG. 73, a drain conduit 630 is formed integrally with the toilet body 611 to work as a flow path of water and excrement and is disposed after the drainage port 625, which is formed behind the recess 626 working as the excrement reservoir. The drain conduit 630 has a connection pathway 631 that is curved in an oblique upward direction from the drainage port 625, an ascending pathway 632 that is extended in the curved direction of the connection pathway 631 and is then curved in a lateral direction, and a descending pathway 633 that is curved in the lateral direction and subsequently in a downward direction. The end of the descending pathway 633 is connected to the drain conduit P, which rises upward from the floor surface FL of the lavatory at the installation place of the toilet, via the resin drain socket 670.

[0449]FIG. 75 is an enlarged sectional view illustrating the vicinity of the drain socket 670 of FIG. 73. The drain socket 670 shown in FIG. 75 includes a toilet joint member 671, a connection conduit 673, a drain conduit joint member 674, and a socket fixation member 678, which are integrally made of a resin.

[0450] The toilet joint member 671 receives the lower end of the descending pathway 633 of the drain conduit 630 fitted therein and is thereby linked with the drain conduit 630. The connection conduit 673 is extended below the toilet joint member 671, and receives the drain conduit P fitted therein, so as to be positioned relative to the drain conduit P. The drain conduit joint member 674 is formed downstream the toilet joint member 671 and inside the circumference of the connection conduit 673. The drain conduit joint member 674 is arranged to be concentric with the connection conduit 673 and functions as an outflow cylindrical member 675 with a flow outlet 675 a on the lower end thereof. The outflow cylindrical member 675 is inserted in the drain conduit P leading to sewer and thereby prevents leakage of cleansing water. The socket fixation member 678 is formed integrally on the outer circumference of the drain socket 670. The socket fixation member 678 functions to fix the drain socket 670 to the floor surface FL and has a base extended in the horizontal direction from the lower end of the outer circumference of the drain socket 670. The drain socket 670 is fixed to the floor surface FL by screwing the socket fixation member 678 to the floor surface FL with non-illustrated bolts.

[0451] The drain socket 670 also has a cleansing water retention module 680 for inducing the siphon action and a delay module 690 for delaying the flow-out of cleansing water. FIG. 76 is a perspective view illustrating the partly broken drain socket 670 to show the details of the vicinity of the cleansing water retention module 680. Referring to FIG. 76, the cleansing water retention module 680 has a ring-shaped convex 681 (separation convex) radially protruded from the inner wall towards the center. The ring-shaped convex 681 defines a restricted flow path 682 on the center thereof and forms a slope 683 of an obtuse angle on the upper face thereof. The ring-shaped convex 681 has a horizontal length L1 from the inner wall surface. The restricted flow path 682 is narrower than the upstream flow path, while the slope 683 changes the flow direction of cleansing water to form a water film. The cleansing water retention module 680 thereby ensures instant induction of the siphon action.

[0452] The delay module 690 is disposed below the ring-shaped convex 681. The delay module 690 has a guide projection 690 (delay convex). The guide projection 691 is protruded in a continuous spiral form, and has a guide groove 692 and a flow path 693 defined on the center thereof. The guide projection 691 has a horizontal length L2 from the inner wall surface, and the length L2 is less than the length L1 of the ring-shaped convex 681. The ring-shaped convex 681 accordingly hangs over the guide projection 691. Namely, the ring-shaped convex 681 functions as a cover of the guide projection 691. The delay module 690 leads the flow of cleansing water to the flow path 693 when the flow of cleansing water does not reach the guide projection 691. When the flow of cleansing water reaches the guide projection 691, on the other hand, the delay module 690 leads part of cleansing water to the guide groove 692 and makes the part of cleansing water flow down in a spiral form.

[0453] In the toilet 610 having the construction discussed above, discharge of sewage and excrement follows a cleansing process discussed below. Prior to start of a current cleansing action, the reserved water RW supplied by a previous cleansing action is in the bowl 620. The reserved water RW includes water kept in the bowl 620 before the drainage port 625 (hereinafter this water is referred to as the sealing water), water kept in the connection pathway 631 and the ascending pathway 632 after the drainage port 625 (hereinafter this water is referred to as the flow path storage water), and water kept in the lower portion of the retention space 641 a and the jet supply conduit 646 of the toilet 610 (hereinafter this water is referred to as the jet storage water). The water level WL generally depends upon the height of a weir 634, which is the highest position of the lower inner wall of the ascending pathway 632. The lower portion of the retention space 641 a, the jet supply nozzle 645, and the jet supply conduit 646 are located below the weir 634 in the toilet 610 and are filled with cleansing water prior to start of the cleansing action.

[0454] Under such conditions, a supply of cleansing water from the water tank WT is first flown into the retention space 641 a and causes the jet storage water in the jet supply conduit 646 to be ejected via the jet nozzle 622 into the drain conduit 630. The supply of cleansing water that is fed to the retention space 641 a and reaches its upper position is flown through the branch hole 642 and is jetted out of the water outlets 644.

[0455] The cleansing water jetted into the bowl 620 raises the water level in the ascending pathway 632 and makes the curved portion from the ascending pathway 632 to the descending pathway 633 filled with water. The cleansing water then passes through the descending pathway 633 and is temporarily retained by the cleansing water retention module 680. There is a pressure difference between the temporarily retained cleansing water and the reserved water in the bowl 620. This pressure difference generates a downward pulling force, which causes the excrement together with the cleansing water (sanitary sewage) in the ascending pathway 632 and the connection pathway 631 and the cleansing water (sanitary sewage) in the bowl 620 to be vigorously led into the drain conduit P. This process induces the siphon action and causes the cleansing water (sanitary sewage) and excrement in the bowl 620 to be instantly discharged outside through the drain conduit.

[0456] The flow of cleansing water through the cleansing water retention module 680 goes to the delay module 690. The functions of the delay module 690 are discussed below. FIG. 77 shows a time-based variation in flow rate of cleansing water flown out of the drainage port in the cleansing process. FIG. 78 shows initial and midd1e stages in the cleansing process. FIG. 79 shows a terminal stage in the cleansing process. In this embodiment, the behavior of cleansing water by the delay module 690 in the initial or midd1e stage of the cleansing process is different from the behavior in the terminal stage.

[0457] The flow of cleansing water through the cleansing water retention module 680 in the initial stage (a time interval of t1 to t2) or the midd1e stage (a time interval of t2 to t3) of the cleansing process goes to the delay module 690. At this moment, the cleansing water in the bowl 620 has a high water level and a large water head, the flow of cleansing water is restricted by the cleansing water retention module 680 and goes to the delay module 690 at a high flow velocity. As shown in FIG. 78, the restricted flow path 682 of the cleansing water retention module 680 is narrower than the flow path 693 of the delay module 690. The ring-shaped convex 681 accordingly hangs over the guide projection 691 and prevents the flow of cleansing water from reaching the guide projection 691 of the delay module 690. In the initial and midd1e stages of the cleansing process, the flow of cleansing water has a high velocity, so that the delay module 690 allows the direct flow of cleansing water and does not interfere with smooth drainage.

[0458] In the terminal stage (a time interval of t3 to t4) of the cleansing process when the flow rate of cleansing water is decreasing from its peak value, the water head is abruptly reduced with the decrease in flow rate and thereby lowers the velocity of the downward flow. As shown in FIG. 79, the circumferential force of cleansing water becomes relatively greater than the downward force. The flow of cleansing water accordingly goes to the inner wall and is flown down in the spiral form by means of the guide projection 691 of the delay module 690. The cleansing water flows in the spiral guide groove 692. The spiral flow takes a longer time than the straight downward flow. In the terminal stage of the cleansing water, the increased fluidity resistance of the delay module 690 extends the discharge time of cleansing water. This arrangement shifts the conventional variation in flow rate shown by the two-dot chain line to the variation in flow rate shown by the solid line in the graph of FIG. 77. The discharge time of cleansing water is accordingly extended from the time point t4 to a time point t5 in the terminal stage of the cleansing process.

[0459] The flow of cleansing water through the drain conduit 630 quickly discharges excrement in the initial or midd1e stage of the cleansing process having the large flow velocity, while being delayed in the terminal stage of the cleansing process having the small flow velocity. This arrangement enables even floating excrement in the bowl 620, which requires a relatively long time for discharge, to be discharged from the bowl 620 without failure.

[0460] The same flow rate of cleansing water as the conventional level slightly lowers the peak but still ensures the sufficient force required for discharging excrement.

[0461] The cleansing water retention module 680 and the delay module 690 are provided in the drain socket 670 and are formed separately from the toilet body 611. Even the cleansing water retention module 680 and the delay module 690 having complicated shapes can thus be manufactured readily.

[0462] The fifteenth embodiment discussed above may be modified as follows:

[0463] The cleansing water retention module 680 and the delay module 690 may be formed integrally with the toilet made of pottery by utilizing a plaster or resin mold.

[0464] (2) In the above embodiment, the delay module is the continuous guide projection in the spiral form. The delay module is, however, not restricted to this shape, but may be a spiral form with one or multiple notches or include multiple steps protruded in the horizontal direction.

INDUSTRIAL APPLICABILITY

[0465] The technique of the present invention that efficiently induces the siphon action for smooth discharge of excrement from a bowl is favorably applied to a toilet, a drainage device for the toilet, and the lavatory with such a toilet. 

1. A drainage device of a toilet, comprising: a drain socket that has a flow inlet connecting with a drainage port of a toilet body, a flow outlet connecting with a drain conduit leading to sewer, and a socket flow path connecting the flow inlet with the flow outlet in an eccentric layout; and a restriction element that is formed integrally with the drain socket and causes a flow of cleansing water flowing through the socket flow path to be temporarily retained, so as to induce a siphon action.
 2. A drainage device of a toilet in accordance with claim 1, wherein the restriction element has a restricted flow path that is eccentric to the socket flow path with the restriction element.
 3. A drainage device of a toilet in accordance with claim 1, wherein the restriction element is located in a neighborhood of the flow outlet.
 4. A drainage device of a toilet in accordance with claim 1, wherein the drain socket comprises a fixation unit that is fixed to a floor surface, the socket flow path has a conduit that is located below the fixation unit and has an outlet inserted in the drain conduit, and the restriction element is disposed in the conduit.
 5. A drainage device of a toilet in accordance with claim 1, wherein the restriction element is formed separately from the drain socket, the drainage device further comprising an attachment module that detachably attaches the restriction element to the drain socket.
 6. A drainage device of a toilet in accordance with claim 1, wherein the toilet comprises a toilet restriction unit in a neighborhood of a drainage port.
 7. A drainage device of a toilet in accordance with claim 6, wherein the toilet restriction unit is located to be eccentric to the flow inlet.
 8. A drainage device of a toilet, comprising: a drain socket having a toilet connection member with a flow inlet that connects with a drainage port of a toilet body, a drain conduit connection member with a flow outlet that connects with a drain conduit leading to sewer; and a socket flow path that connects the flow inlet with the flow outlet; and a cleansing water retention module that is formed separately from the drain socket, is fixed to the drain socket, and causes a flow of cleansing water flowing through the socket flow path to be temporarily retained, so as to induce a siphon action.
 9. A drainage device of a toilet in accordance with claim 8, wherein the cleansing water retention module is designed to change a flow path area in a flow direction of cleansing water.
 10. A drainage device of a toilet in accordance with claim 9, wherein the cleansing water retention module is located in the socket flow path and is designed to continuously decrease a flow path area from an upstream side to a downstream side.
 11. A drainage device of a toilet in accordance with claim 8, wherein the cleansing water retention module comprises a restriction element that narrows a flow path area of the socket flow path.
 12. A drainage device of a toilet in accordance with claim 11, wherein the restriction element is formed to reduce its flow path area from an upstream side to a downstream side.
 13. A drainage device of a toilet in accordance with claim 11, wherein the cleansing water retention module has an enlarged flow path, which is formed upstream of the restriction element to have a greater flow path area.
 14. A drainage device of a toilet in accordance with claim 11, wherein the restriction element is provided in a neighborhood of the flow outlet.
 15. A drainage device of a toilet in accordance with claim 11, wherein the cleansing water retention module has a plurality of the restriction elements arranged along a flow of cleansing water.
 16. A drainage device of a toilet in accordance with claim 8, wherein the cleansing water retention module comprises a fixation unit that is positioned and fixed to the drain socket.
 17. A drainage device of a toilet in accordance with claim 8, wherein the drain socket has the socket flow path that connects the flow inlet with the flow outlet in an eccentric layout, and the cleansing water retention module is disposed in the socket flow path. 